If you find yourself in Sao Paulo make sure you stay at the Sheraton Moffarrej.  It is a five star hotel with great suites and a very nice pool, also the bartenders are great and make a mean caiparinha;-)  If you are on a budget the George V is the place to stay, it is close to shopping and the rooms are quite spacious.  Even though Sao Paulo is a very large and an industrial city (i.e. polluted) it has some great parks.  Your visit should include Parque do Ibirapuera, the Zoological gardens and the guided safari.  Sao Paulo also has some great architecture.  Make sure you see the Cathedral da Se, it is beautiful.  If you visit Sao Paulo or Brazil in general make sure you bring your appetite because most restaurants are Churasso style which is where the waiters bring around various types of meats until you are finished.  Two places I like are the Barbacoa and Qunita do Mandioca.  Enjoy....