There are numerous excellent resources for this type of instruction. Beyond what's already available on PerlMonks, I can highly suggest the following books:

Programming the Perl DBI, O'Reilly
CGI Programming with Perl, O'Reilly
Writing CGI Applications with Perl", Addison Wesley (an absolutely incredible book!!!)

In addition, a few googled links...

http://www.danchan.com/feature/2000/10/16/mysql/mysql3.htm
http://dbi.perl.org/doc/index.html
http://www.mysql.com/doc/P/e/Perl_DBI_Class.html

Hope this helps!

-fp