There are CDs and lots of good books out there. But have you tried
FishBase? It’s
a global catalogue and easy to search (try common name lion fish, for example), presenting a wealth of other info to explore.
http://www.fishbase.org/home.htm The Smithsonian Tropical Research Institute has recently released a similar system for the
eastern Pacific inshore species only. It’s a bit slower, and more scientific in approach, but a good primer on this particular area:
http://www.neotropicalfishes.org/sftep/index.php