Yes, there are many books on codependency. Codependent No More
, by Melody Beattie was one of the first of these self help books, published back in 1990 I think, my sister and I went to hear her speak at a local book signing. She's written at least a dozen more books on the subject since then. I love her daily meditations book.
Other authors I've read are Robin Norwood, Joyce Meyer, Karen Casey and John Bradshaw (years ago Brawshaw had a great series on PBS about dysfunctional families, I think it's still available).
Many counselors and therapists specialize in codependency issues.
Codependents Anonymous (CoDA) is a twelve step styled support group, local listings should be in your newspaper. I found the quality of these meetings vary widely though - some are very well run, supportive and informative. Others only have a few people and it ends up like a coffee get-together, just gossipy talk. That's true of most informal support groups, IMO, the bigger the better.