Sao Paulo

Things to do
Old city centre
Municipal Food Market (“Mercadao”): http://www.mercadomunicipal.com.br/home.html. (in the section “localizacao" there is a good map showing subway stations or metros). Great for fruit, spices, cheeses, butchers, cured meats (the “mortadela" sandwich is a classic). Worth visiting also for the architecture, and definitely for the buzz. The market opens daily (including holidays) from 6am to 6 pm or 4pm (sundays and holidays).
and here's the museum that is not too far from it http://www.pinacoteca.org.br/ (info in English). It is a rough (not as in dangerous, but just impoverished) but historical part of town, i find it worth visiting. For food in this area, try Bistro da Sara for a fantastic, creative buffet lunch in a very charming venue (Rua da Graca 32 Bom Retiro) for a proper lunch, or for quick bites, Falafel Malka (inside a gallery on 345 Rua Jose Paulino) or amazing burekas at Casa Bulgara (Rua Silva Pinto, 356).
Also in this area is Estacao Julio Prestes, a former train station and now a concert hall -http://www.salasaopaulo.art.br/eventos/infoGeral.aspx
and if you're into shopping sao paulo is famous for its malls (Iguatemi and Cidade Jardim probably the nicest), and the area around rua Oscar Freire is also very nice.

A night club I used to like was lov.e http://www.tripadvisor.co.uk/Attraction_Review-g303631-d675972-Reviews-Lov_e_Club-Sao_Paulo_State_of_Sao_Paulo.html. another cool, more relaxed (earlier hours) place is Grazie a Dio, great for live music. http://travel.nytimes.com/travel/guides/central-and-south-america/brazil/sao-paulo/30077/grazie-a-dio/nightlife-detail.html

Sao Paulo has a million amazing great places for street food (you'll be fine in the Mercado area) and quite a few ridiculously expensive and excellent restaurants. My favourite pick (not too expensive, especially if you get the lunch menu on a week day) is Brasil a Gosto. http://www.brasilagosto.com.br/site/

Great tips also on this link:http://riotimesonline.com/news/rio-travel/48-hours-in-sao-paulo/

Other restaurant picks

KAA - good food, gorgeous setting
Brasil A Gosto
Arturito - well executed, a bit overpriced
Chou - creative Brazilian tapas, another of my favouritesCafe' Octavio



Ene - Spanish tapas, the real thing.

Can't wait to try:
Alma Maria - Rua Oscar Freire, 439. 30640047. also tapas, chef Tony Botella form Barcelona. Montaditos are the main stars, wines by the glass from R$15. 



Japanese
Aya. My new passion. Each piece of sushi is artfully crafted, perfectly executed. 
Mori Sushi. Rua da Consolacao 3610. www.morisushi.com.br 38982977. Really differentiated "all you can eat" proposition. Sophisticated combinations, very nice hot starters. Includes Hagen Dasz ice cream for desert. Bill was R$70 per person - but we only drank tea. Pretty reasonable for the quality and quantity.