A beginning programmer might think to write separate cgi scripts for each task (display, insert and delete) but I'd prefer a single script to keep it all together to make changes more simple. Call the script with a "mode" argument to trigger the right functions to display the forms and have them react appropriately. Make certain to consider security since this is usually necessary even for an intranet environment.

Since you already have the Perl-MySQL part done, the documentation for the standard CGI module can probably give you the rest. This includes a few examples to build from.

If want a recommendation for a book, you might look into the PerlMonks' Reviews, e.g., MySQL and Perl for the Web.