You might want to take a look at this very good book:
Mastering Algorithms with Perl, by Jon Orwant, Jarkko Hietaniemi and John Macdonald (O'Reilly). Chapter 9 ("Strings") has quite a bit of things about fuzzy matching and other interesting things. The good thing about it is that it gives you not only Perl solutions (such as using the XYZ module), but also some solid CS theory behind, with important known algorithms, etc.
It might be out of print, but I did not have too much trouble finding it second hand on the Internet a couple of years ago, or so. And it is a really "nice to read" and "nice to have" book. It definitely helped me several times when I had to tackle a subject really new to me (or long forgotten).
You might prefer The art of Computer Programming, the bible of programming by Donald Knuth, which I am also using relatively regularly (probably being a bit of a masochistic), or the famous Cormen et al. textbook, but the good thing about Mastering Algorithms with Perl is that it is usually easier to grasp and is directly related to our (well at least my) favorite language.
