Someone earlier mentioned "Two Years before the Mast." I tried reading that once—I never finished it—and I found the nautical parts to be nearly unintelligible. At least, to understand them, I would have needed frequent reference to a dictionary, maybe even a specialized nautical dictionary. Maybe there exists an edition with lots of footnotes, diagrams, and other explanatory material, but that's not what I had.

This might be useful: List of sailing boat types from Wikipedia. It seems to be an index page for all sorts of information about sailing ships.