João Pessoa - Paraíba Paradise > Bureaucracy > Banking > ATM's
Make sure you have a four-digit PIN (longer PINs may not work). In general HSBC, Citibank, Banco do Brasil and Bradesco are the best ATMs to try.
Look for the stickers on the machines that say Cirrus, Visa, or whatever system your card uses, though this may not mean the machine will necessarily work.
Do take care when using ATMs; there have been a number of scams, where criminals have managed to hack into bank accounts of ATM users and subsequently drain them.