The best way to find out about how a college handles AP classes is to ask them. Some colleges will give credit only for 5s, some for 4s and 5s, some for 3s, 4s, and 5s if it's not a class in your major, some not at all if the class is part of a major. It's not always an easy question to answer, but Academic Services (or the equivalent) as well as Admissions Counselors are used to finding out the answers for you.
I started college with 17 credits after earning 5s on US History, English Lit, and English Comp and a 4 on Biology. Probably unlike many colleges, I got 3 credits each for US History and the English exams, but *8* credits (2 semesters plus labs) for Biology.
Also remember that every school may handle credits differently. For instance, at Rutgers, credits are calculated by # of hours/week spent in a class each semester, while at Brown, each class in a semester is one credit.
~Ladi