For a good pronunciation guide, I'd recommend
Allen & Geenough's New Latin Grammar
on the Perseus site.
However, that is not the way I pronounce Latin. That site teaches the
pronunciation that most scholars agree was used in ancient Rome. I
learned what is sometimes called "Ecclesiastical" Latin pronunciation. This
is how Latin came to be pronounced in its later use as the language of
scholars and of the Church.
Take the word
cælum (heaven) for instance. They would pronounce
it "KI-lum" (long i). I would pronounce it CHAY-lum.