Concur with above writer. But for 10-day trip, I would stay in Rio to explore greater area. Salvador is great. But I like 1 full trip instead of 2 half-trip. On greater Rio:

* A great hidden jam is Paqueta Island. A ferry ride and total escape from urban Rio. horse carriages and no cars! get a bungalow for 2-day stay, and your kid can run free.

* Petropolis forest city is another worthy 2-day trip. Many tours run day trips but it's definitely big and different enough for an overnight.

* Tijuca Peninsula is a great contrast from Rio for high-rise living with modern malls. Take a bus from Copa and just stop at few major centers along the way.

since your trip is months away, you may want to start following its travel scenes for fresh stories down the road. you can do that easily here:

http://www.travelogx.com/rio