Rio - Ipanema and Copa for people watching and hanging out during the day. In the evening, go to Lapa (http://en.wikipedia.org/wiki/Lapa,_Rio_de_Janeiro)
Salvador - historical centre is Pelourinho, but better to stay at Bahia, nice beach and a more chilled vibe, less tourists. about 5 years ago
In Rio de Janeiro some of the best beaches are Ipanema and São Conrado.
The best (and safe) nightlife is at Lapa (a neighborhood).
When it comes to prices, Rio isn't exactly the best place for shopping, unless you're after local products (for this there are many fairs and street markets). Anyway, the place is well served by some malls, like RioSul and FashionMall. about 5 years ago
There are many historical places in Salvador, it was the first capital of Brazil, so it is a place full of history and interesting things to see and do. As for the beaches, the best ones are out of town, but there is a special piece of beach, where locals from the charming district of Rio Vermelho usually go that is called Buracão, there you will find lots of beautiful people and it is very safe. As for the nightlife, Rio Vermelho is considered the bohemean area of the city. If you are in town on a Saturday, don't miss the Jam no MAM. It is a jam session by the sea at the Museum osF Modern Art. It starts with the sunset and it is really amazing and cheap. It happens all Saturdays for the past 13 years. You can also e-mail me if you need and help. firstname.lastname@example.org
Hope u have a safe and happy trip to Brazil. about 5 years ago
Ipanema and Copacabana are the safest beaches to go, certain, but try to visit Prainha or Grumari: they are the best ones! For nightlife Lapa is always a good solluction, but there're few nightclubs in Zona Sul or Barra there're good too, you just have to ask for them (: and about shopping: don't do it in Rio, it's really expensive!!! about 5 years ago