Do community colleges have good math libraries? Do community colleges have good mathematics libraries (with advanced books)? I am sure that it is different from place to place. I am interested to get some feeling of the general situation.
Of course, as Dave Clarke says, every institution is different.  However, in general I would expect the answer is no.

Community colleges typically offer only lower-division courses and don't expect their students or faculty to carry on research.  Moreover, they are usually publicly funded and charge only nominal tuition, so they are not likely to have a lot of extra money.  Given this, it's difficult to see why a community college librarian would want to spend money acquiring advanced mathematics books or journals.

That said, a community college library would almost certainly have access to the interlibrary loan network, allowing one to (eventually) acquire any resource of interest.  Some might also have a reciprocity agreement with a nearby research university library.  It is also quite possible they would have access to online databases that could include a lot of material in mathematics.