Learn the language or as much as you can is very good advice.
I've been there a number of times for work and as my language skills improved, my overall experience improved also.
Be sure to visit a Churascaria, this is the equivalant of our all you can eat buffet but they bring the food to you at your table. Lotso beef, be sure to try the Picanya.
Skol beer was the best I tried but I can't recall a bad beer while I was there. The locals drank a sugar, water, liquor and lime drink called a Ceipadea(sp?) which was very strong and resulted in quite a few early nights for the Americans that tried it.
Sao Paulo was a crime ridden shithole, I would advise if you are out enjoying the nightlife which is in abundance, Brazilians love to party, use the buddy system.
Enjoy your stay.