Books are invaluable to all aquarium fish owners, from beginner to advanced. Here are my top choices for books about Bettas, Gourmis, and other Labyrinth fish.
Aqualog All Labyrinths
Aqualogs are designed to maintain consistency fish identification, regardless of nomenclature changes. Each fish has at least one color photo, basic information, and a description. Regular updates are published to keep the original volume up to date. This volume covers all anabantoid fishes, snakeheads, nandids, and related families.
Bettas
Marshall E. Ostrow is recognized as a leading authority on bettas. In addition to care and breeding information, this book has a wealth of excellent betta photos. Although it no longer in print, it's well worth tracking down a copy.
Labyrinth Fish: The Bubble Nest Builders
This easy to read book covers all species of Bettas, Gouramis and Paradisefish. It includes care, feeding, breeding, and health information, as well as many color photos. Out of print, but used copies are readily available, and are worth looking for.Gouramis and Other Anabantoids
This is another out of print book that is well worth looking for. Includes a wealth of information about a wide variety of Anabantoids, complete with full color photos.Complete Introduction to Bettas
A nice little book that covers care and breeding of Bettas. Easy to read, and inexpensive. Geared for the beginner, even young Betta owners will enjoy it.Labyrinth Fish
Like many of the better books on this subject, this book is also out of print. However, you can still find plenty of used copies. If you are interested in labyrinth fish, you'll care information about find dozens of species.