Alot of Squeaking, PLEASE help!!!!!!

Ok, i have a 2001 Pontiac Grand prix SE with the 3.1L V6. The Car has a ton of squeaking when you tap the break and go to stop at a red light or any kind of break pressing, exept when you press it really fast, which you cant always do. Whats the problem here and what needs to be replaced to stop the squeaking its driving me insane and how much would this cost?????

thanks for ANY help you can give to me!!!:banghead:

sounds as if you need brake pads and rotors,hopefully the pads are not digging into the rotors to cause damage,other wise$$$$$$$$$$$$$$