This comprehensive book (the equivalent of about 604 print pages) covers almost every aspect of shell scripting. It contains 299 profusely commented illustrative examples (including such goodies as an anti-spammer script), and a number of tables. Not just a shell scripting tutorial, this book also provides an introduction to basic programming techniques, such as sorting and recursion. It is well suited for either individual study or classroom use.

freshmeat.net/redir/advancedbashscriptingguide/130/url_homepage/html