The Barrons books are all excellent for all subjects. I have them for plants and several subjects. They do not talk over your head and they give a lot of really good information about everything. Some of the books give the information but you need a medical degree to understand them. I have a book about Fish Disease in general that I use a lot that is not technically just a betta book but says a lot and gives a really good place to start when you just do not know what it may be.
I buy most of my books at Amazon.com as you can buy them used and always check the used section as a lot of the "used" ones will be new but have a smudge or folded page and so cannot be sold as new. They do not charge a lot for postage and they have great books.
Ok. Again thanks for all the info. I'm really wanting an in depth, detailed book and have a feeling these books may be a little on the "basic" side from what little bit I was able to skip over.....but it sounds like these are my only options. lol
These books get pretty specific actually. You might try a good browsing at the local Barnes and Noble or Public Library. Or if you are lucky enough to live in a University town, go to their library and browse. They will not allow you to check out the books but you can look and see if you find one that fits what you want. There are books that cover fish in general that are huge and complex but the books that Butterfly listed are really comprehensive about bettas and cover pretty much all of their anatomy, breeding, types, species, and other information. You will be surprised actually. The Barron's Books are wonderful and I believe they actually have 2 on Bettas.
I have a whole bookcase and floor full of fish and plant books and a lot of references but most of them are not limited to ONLY bettas. They contain a lot of very good information about them but you have to find it as part of the book about freshwater aquarium fish in general. I also have articles from some of the magazines I have received that carried good information on bettas, but again, most of the time when you get great information, it is mixed in with information having to do with other fish as well. Most of my VERY best reference books that have the MOST details and information down to the nitty-gritty are not specific to the bettas at all. (but Bettas play a very good part in their own section)
I went to Barnes and Noble Sunday night and they didn't have any fish specific books. It was all stuff like "setting up your aquarium" or just talked about aquariums in general. I already know the basic stuff like that. Same thing with the library. I finally just bought one from Amazon, the one from the Animal Planet series.