Getting to know the language and people. by Carpo
If you want to learn a little about the language before you arrive there are a couple of good books I can recommend.The first one is "How to say anything in Portugese" by Ron Martinez. It is full of useful phrases and advice on manners and has a lot of explanations for some of the strange things Brasilians do.
The second one is "How to be a Carioca"; unfortunately I cannot remember the authors name. It is more of a guide to living in Rio and surviving the strange customs and rules of the city. It also contains a lot of useful slang.
A third good book is "Rio for partygoers"; it is a guide to the bars and clubs in Rio and the type of characters that frequent them. It also has a useful guide to local customs for flirting and dating.
