When you find a good book - look around the shelves in that area for more. You are guaranteed to find something browsing you miss keyword searching the catalog. Explore tables of contents and indexes in books that catch your eye
Texts in translation published as books are your key primary sources.
Recent studies in scholarly journals will cite the most current translations of primary sources
Web sources usually only present excerpts of a work. These are great sites to explore, but look up the full version of the source in the library catalog.