Holiday: Brazil: leaving in end April-Beginning May?

You don't say where you are travelling from. Actually i'm off to Brasil for a month a week on Sunday. My wife has family in Sorocaba (Sao Paulo State). I'm travelling from Scotland myself. Sao Paulo is huge & like verywhere you have to take care in the city. Pay special attention on the underground as pickpockets are rife there. I've only visited Sampa (Sao Paulo) once, but it seemed that with the correct precautions it could be a great place to visit.