When I first got into the hobby of keeping an aquarium, I purchased a book called "The Tropical Fish Encyclopedia." It lists all species and is very informative.
You should go to a Live Fish Store (pet store specializing in fish)in your area. At any Live fish store, you should be able to find books and charts showing all varieties of tropical fish.
If you do a search on Amazon dot com, you should be able to find quite a few titles regarding tropical fish species. You can search by topic or search a specific section of books.
