There is more to life than just reading. And I don't think that one should have to spend a ton of money on books to support their hobbies. However there are a number of neat titles which could be of use to you.

If you were to go to your public library, when ever convenient, set yourself up at their computer and type in guppies and guppy and "breeding guppies" in their topic search, You would see what they and neighboring libraries have available. Borrowing from a nearby library is your right as a taxpaying member of their library district. My local library borrowed a couple $100 worth of books through interlibrary loan on my behalf last year. Why not? :)

If you feel so lead, one good book for everyone is the Baensch Atlas, vol. 1 especially. That guppy book I was referring to is out of print. I got a copy after a pretty good Internet hunt. But you probably could get the library to find Stan Shubel's THE PROPER CARE OF GUPPIES (TFH Publications, 1995). Guppy Girl, of this site, mentioned a pretty good list of guppy books, a few month ago.

Interestingly, if you were to go to the halfcom site, http://half.ebay.com/index.jsp
and click on books and do a search for "Guppies" you will also get quite a list of books to look for. Again put your library to work.

The search engine on this site has been both useful and useless, but give it a try. Also click through the back diaries and logs here. There is an increasing amount of useful info and discussion which has been generated by good questions such as yours.

If you really want to read about guppies, a google search is also useful. Sites like the IFGA site is helpful and also offers a nice set of links to connect to.