You are already working through Learning Perl - that's a good place to start. As others have suggested, do the exercises.

Also as others have suggested there is a lot of good material here. In the Tutorials section you will find:

• Getting Started with Perl
• CGI Programming
• User Interfaces

which address where you are at and where you are headed.

Learn to use Super Search for finding material stored away in various corners of the Monastery. It is an excellent tool for accessing the resource here.

Enjoy your stay. ;)