Salinópolis (also known as Salinas) is the prime beach resort in Pará. It packs in June and July, and maintains a certain pace on weekends throughout the year.
The bus terminal is about 1 km from the coast, on the main road. Boa Esperança operates buses to Belém, São Luís and Capanema, with many connections. There are also minibuses to Belém, but no transport after 6 PM. Coming from the east, you should change buses at Capanema or Santa Maria. The latter has more and later buses due to its location on the route from Belém. With some luck you could find a boat going to Algodoal
Mototaxis at R$ 3.
Tourists mostly head for the bars along the beach, while locals tend to like Praça Soares Bentes, a few blocks from the bus terminal. On weekends there is always some club, -ask around.
There are hotels and inns everywhere, low season rates from R$ 30 or less, high season seldom under R$ 50 for a single. If you don´t have a car, the best place to stay is probably near the end of the Maçarico beach boulevard. Here there is a small bridge leading straight to the beach of Corvinas.
Internet is a bit tricky, mostly inland and closes early, especially on weekends.