Book by O'Reilly Publishing. A great beginners guide for Perl programming. It's a great starting point and include exercises at the end of each chapter, it's where I started (and where I still am in some respects). Includes basics on CGI scripting as well. After you're done with this you can move on to Programming Perl, The Perl Cookbook(more of a code reference library than a leartning tool, although I could argue with that) and Advanced Perl Programming.