LIVING
If you're unfamiliar with BA, I wouldn't arrange long-term housing before you get down here. Stay in a hostel your first few days here, get the lay of the land, then start looking around.
Craigslist BA: Craigslist postings tend to be way overpriced (because they know foreigners can afford more).
Piso Compartido: http://www.pisocompartido.com.ar/ is a great local apartment locator. It's used by locals so you're roommates will be Portenos and rent is much more reasonable. Website is all Spanish though.
Palermo
My personal favorite part of town. It's the biggest barrio here. Tons of restaurants, cafes, nightlife, gyms, movie theaters, etc. Santa Fe is the big street that runs through it. Try to find a place close to or on Santa Fe to make for easier transportation. The Subte D-line runs along Santa Fe. Plaza Italia (at Sante Fe y Sarmiento) is a major hub for colectivos (city buses). There are some decent parks and running trails in Palermo as well. Palermo Soho and Hollywood have a higher density of restaurants and nightlife. I lived in Palermo Viejo (Santa Fe y Scalabrini Ortiz) and the location was great. Everything you need is nearby: grocery, pharmacy, ATMs, laundromat, and good eats.
Recoleta
One of the pricer parts of BA. Rent is higher. Nightlife is not as great. Has mostly bars and it shuts down by 1 or 2am.
Las Canitas (in between Palermo and Belgrano)
A pricey but great part of town. Has a 2-3 block concentration of great restaurants and bars. Does not have many late night boliches (clubs).
San Telmo
Not sure why anyone would want to live long-term in San Telmo. Besides tango, it doesn't offer much. It's on south side of town and a good 15 minute cab ride to Palermo. And at night, it's not safe. It's next to La Boca, which is a dangerous part of town.
La Boca
Not safe for living in or touring at night. Famous for old port/docks, painted houses, and of course the Boca Juniors soccer team.
TRANSPORTATION
Taxis
Taxis are abundant and very reasonably priced. If you're travelling with at least one other person, the low fares almost always make it the best mode of travel.
Subte (Subway)
www.subte.com.ar for maps. One way trip is AR$1.10. The subte closes at 10pm.
Colectivos (buses)
Definitely the most common mode of transport in BA. The colectivos ONLY take change (monedas), so do not board a bus without any. Costs are anywhere between AR$1.10-$3.50. www.comoviajo.com is a GREAT website to determine the optimal bus route between any two points. Very very handy.
Guia T
This is a hand-held city map that everyone should own. Also, has information on colectivo routes. Can be purchased at most kiosks.
AIRPORT TRANSPORTATION
Ezeiza (International flights)
Taxis will run about AR$130 to Capital (Palermo/Recoleta/Microcentro/etc). Recommend: Manuel Tienda Leon shuttles are about AR$45 one way to/from their hub in Microcentro (downtown). You can reserve online at www.tiendaleon.com.ar. 45-60 minute trip from downtown.
Aeroparque/Jorge Newberry (Domestic flights)
Taxis from Palermo are about AR$25 and about a 15 min drive (no traffic). Domestic airlines to choose from: Aerolineas Argentinas and LAN.
CELL PHONES
Pay-as-you-go phones are typically the best option. There are three main providers: Movistar, Personal, and Claro. Movistar probably has the best coverage. Your best option is to buy a local SIM card at one of these providers' stores and put it in your US-based phone. However, for reasons unclear, this is NOT possible for an iPhone. So, if you have an iPhone, I recommend two things: 1) buy a cheap/old phone in the states before you go down to BA (because the cheapest phone in BA will cost US$50), and 2) temporarily suspend your service with AT&T (to ensure your iPhone doesn't accidentally download data in BA, which costs a fortune). You can do this (and undo) with a click of a button online. You will still be able to connect to Wi-Fi. Note: When you suspend your service, you still pay your bill 100%.
Skype
A cool tip with Skype for iPhone users. Download the Skype application and you can use it just like a phone wherever you have Wi-Fi access. Costs about 2 cents/min to the states.
FOOD
Besides the hundreds of inexpensive, quality food spots that BA has to offer, here are several personal recommendations:
Parilla La Escondida: One of the rare BA steak houses that come with warm bread rolls and a great salad bar. The meat and wine are, needless to say, great. Expect to spend a reasonable $US15-20/ea if you're with a group (includes wine and tip). Costa Rica 4464 -- Plaza Armenia in Palermo Soho.
Sushi Club: Some of the best sushi in town. Located in Las Canitas. Expect to spend US$20-25/ea if you're with a group (includes drinks and tip). I recommend the Spicy and Apple rolls as well as the Sambayon de Maracuyita cocktail. Has outdoor seating if the weather is nice. Consider getting drinks beforehand at a number of outdoor bars nearby. Baez 268 -- Las Canitas.
Sarkis: voted #1 mediterranean/middle east cuisine in BA, and appropriately so. The food is great (and offers a nice escape from typical BA cuisine). Order several dishes and share between a group. Prices are VERY reasonable, if not cheap, for the quality. Expect to spend US$10-15/ea if in a group (includes wine and tip). Thames 1101 -- Palermo Soho.
Miranda: one of the nicer parillas in BA, located in Palermo Hollywood. I had the best cut of steak there in my entire trip: the ojo con el bife. Expect to spend US$20-30/ea if in a group (wine and tip included). 5602 Costa Rica -- Palermo Hollywood.
Tandoor: great, authentic Indian food. An upscale restaurant and a little pricey. Expect to spend US$15-25 (wine and tip included). Laprida 1263 -- Barrio Norte.
Las Lilas: one of the premier steak houses in BA. Located in Puerto Madero, on the water. Great outdoor seating if weather is nice. Expect to spend US$35-$50 (includes wine and tip).
Other Argentine 'delicacies':
Choripan (aka 'Chori'): the Argentine version of a hotdog. Chorizo inside a baguette, preferably with chimichurri sauce on top. Puts the hotdog to shame. Can be found at parillas and at street trailors.
Milanesa Napolitana: this is essentially chicken friend steak (or chicken) with cheese and tomato on top. Delicious.
Tarta: somewhat like a stuffed pizza slice, it comes with ham, cheese, egg, and tomato.
Empanada: the classic delicacy. A stuffy pastry can come with meat, chicken, ham & cheese, and many other types.
NIGHTLIFE
BA has an impossible number of bars and night clubs. Here are some of the good...and bad:
Bars
El Alamo: this is the quintessential expat sports bar. Expect to see a lot of study abroad students and other English-speakers. Great for watching American sports. Plenty of good, cheap beer on tap. Gets crowded early on, ie 10pm. On weekends, don't expect to get in after 2am. Uruguay 1175 -- Recoleta.
Casa Bar: the other quintessential expat sports bar. Probably best American sports bar equivalent in BA with quality wings and other sports food. Rodriguez Pena 1150 -- Recoleta.
Milion: overrated and overpriced. The bar is inside a renovated old Mansion but that very fact makes it difficult to walk around. Drinks are expensive and crowd is more on the 'posh'/prententious side. Not a great place for singles as it's a couples hangout. With a million of options in BA...I wouldn't recommend it. Parana 1048 -- Recoleta.
Sugar: in Plaza Armenia. Great bar for having a drink and not much else. Nearly impossible to get into after 12am. They have a very low capacity. Don't recommend it.
La Bomba del Tiempo: Mondays at Konex. This isn't a bar but a Brazilian drum/beats show. They sell beer and food and it's a fun atmosphere. Lasts from 8-10pm. AR$20 cover. Niceto Vega 5510 -- Palermo.
There are a ton of great bars in Las Canitas, all within walking distance of each other.
Boliches (clubs)
Club Kika: if you're looking for something Tuesday night, this is the place to be. Tuesday nights at Kika are hip hop nights and the music doesn't disappoint. Also, has an adjacent dance floor with more electronica/latin music. Make sure you put yourself on the "list" via their website, to avoid paying a cover charge (AR$40). Honduras 5339.
Belushi: next door to Kika. I never went but it sounds like a great place. They have separate areas for bars, lounge, and dance floor. For all tastes and interests. Anywhere from 80's music to electronica, depending on the night. Honduras 5333.
Liquid: on Saturdays, great music: typical top-40 US Charts on lower floor and latin music on second floor. Great area in the back that's more quiet and lounge-like. Free cover on Wednesdays. Santa Fe 3651.
Club Araoz - Lost: The best spot to be on Thursday nights -- hip-hop night. Araoz 2424.
Crobar: If you're looking for the quintessential huge techno club, this is it. After 1am, expect a constant supply of techno/electronica until 6am. And lots of sweat. Cover is AR$50. I don't recommend it. Paseo de la Infanta -- Palermo.
Jet Lounge: Expensive, inconvenient location (near airport), pretentious crowd, loud. It sucks. Rafael Obligado 4801.
Pub Crawls
Buenos Aires Pub Crawl: if you don't mind mingling with other foreigners, it's a great pub crawl. It goes on Wed - Sat nights. The cover includes free entrance to a boliche at the end of the crawl. The only bad part is that the boliche is typically Crobar (see above).
SPANISH LESSONS
Private
If you're living in the Palermo / Recoleta area and looking for private lessons, I recommend Marco Luccon. Great instructor and very affordable: AR$35/hr. He's an English major at the local University, in his late twenties, and tutors in the afternoons. He's located in Palermo Viejo, near Plaza Guemes. info@hablarenbsas.com.ar. tel: 114.825.7817.
Group
Spanglish: checkout out www.spanglishexchange.com for an opportunity to meet some locals and practice your Spanish. It's set up like speed dating where you rotate tables. Thursday nights are the best. Spanglish also offers group classes.
MAIL -- POST OFFICE
If you're expecting a package from the states, there is a good chance it'll go through Correo Argentina. They have several offices around town but their main warehouse is in Retiro. I received a package from USPS and it took about 7 days to ship, 4 days to clear customs, and another 3 days to receive a note in the mail saying I had to pick it up from the Retiro office. So, expect at least 2 weeks all in all.
SOCCER -- FUTBOL
I recommend seeing a Boca Juniors home game at La Bombanera. Games are typically played on the weekends. The stadium is in Boca and is about a AR$35 taxi ride from Palermo. You can buy tickets from scalpers outside the stadium several days before the game and even immediately before. The only problem is you're never assured that the ticket you're buying is real. Tickets should cost no more than AR$70-80 if you're scalping.
Your other option is purchasing a ticket through an "agency". A local secures the ticket for you, takes you to the stadium, and sits with you for the game. Tickets can cost up to AR$300, however. Not a cheap option but you're assured of actually seeing the game. A quality agency: 4922.4409, ask for Guido, and be ready to speak Spanish.
BUENOS AIRES SIGHT-SEEING
BA Bus Tour: the company offers a double-decker bus tour around the city, stopping in all the major neighborhoods. You can get off and tour the neighborhoods at will, as the tour buses come by each stop every 30 minutes. AR$70. www.buenosairesbus.com.
Ecological Reserve in Puerto Madero: on weekends you can rent bikes and bike through the reserve. Some great views of downtown and of the "beach" overlooking the river. The food stands next to the reserve have some of the best Choripan in town.
Tigre: if you're looking to escape from the city for a day, take a tour of Tigre, one of the provinces outside of Capital Federal. Tigre is located on the river delta and is beautiful. You can take boat tours through the tiny river inlets. It also has a small amusement park as well as a market on the river where you can buy anything from mate gourds to leather bags. Tigre also has a casino.
EXERCISE
Gyms
There are gyms all over town. Megatlon is one of the premier, and more expensive, chains in BA. Several of the Megatlons, as well as other local gyms, have indoor lap pools.
Jogging
Los Bosques de Palermo offers decent running trails. It starts at the intersection of Libertador and Sarmiento and goes northwest from there. The Ecological Reserve in Puerto Madero also has great running trails but is harder to get to.