I still have every fish book I ever bought, going back to the mid 70's
and some info has changed over the years. Besides books check out some
of the on line sources like the Krib and check into some magazines out
there. I like "Tropical Fish Hobbyist, The leading Aquarium Magazine
For Over Half a Century" There are a lot of great articles in there.
They also have a web site http://www.tfh.com which may help.

Vicki