Guaruja Beach
If you want to go to a beautiful beach in a scenic setting, then arrange for bus transportation to Guaruja. It is the closest beach to the city (about 1 hour 15 minutes from the bus station to arrive & return in the slower season (March)). The travel books don't talk much about it, and hotels and tour operators may try to take advantage by arranging a private trip or sending you somewhere further away. This is a hidden gem where you won't see much more than the locals and residents of Sao Paulo.
Bus lines that run to this area are in good condition-clean, new, comfortable. The bus station in Sao Paulo is called Jabaqura Bus Station; it costs $50 Reals to take a taxi to this station from the Jardim Paulista area.
There are several bus lines to choose from: Ultra, Brasileira and Litoranea.
You may want to have your hotel concierge to write two notes in Portuguese for the taxi drivers - one for when you get there, to take you to the Hotel Casa Grande which faces a nice area on the beach; a second note to get you back to the bus station in Guaruja.
When it's time to leave, go back to the Hotel Casa Grande and ask the doorman to call a taxi (you also may want to tip the doorman to thank him).
P.S. The locals are nice people so be nice and respectful to them. Also, if you are uncomfortable seeing families of all shapes & sizes wearing thong bikinis and men in speedos, this beach may not be your cup of tea.
Rio de Janeiro
A great one day trip from Sao Paulo is a trip to Rio de Janeiro. It is just a short flight from Sao Paulo (40min flight, about 100 USD each way). A pre arranged taxi can take you from the airport on a tour of the city. A fair price for aprox. 6 hours tour is around 70USD per person (between 2 or 3 people), but be prepared to bargain. Most of the taxi drivers will not speak English but they understand Spanish which might be helpful too.

The first place to visit is Corcovado (14 Reals for a ticket) with the famous Jesus statue. It gets very hectic later in the day, and it will be hard to take photos with so many people around. Then to the Sugar Loaf Rock (37 Reals for a ticket) where a cable car takes passengers to the most amazing view point. After that it’s time for a lunch break at a typical Brazilian restaurant near the Copacabana beach (set menu price is about 39 Reals with all you can eat meat, sushi, salads and desserts).
A walk on the Copacabana beach and then about 10 minutes drive to see the Ipanema beach will help finish the day in true Brazilian style. From there off to the airport again and back to Sao Paulo for aprox 5pm.
A great day out and wouldn't know Brazil without seeing Rio!