Supposing that "kind of stuck with Term::Cap" means that you are stuck with a tty interface...

You may want to have a look at Curses::Widgets and Curses::Forms. These would give you a higher level interface to a tty-based "gui", that would look and feel more similar to Tk and/or GTK.

If this isn't the case, I highly recommend the Tk module. There's a book called "Learning Perl/Tk" that contains a tutorial. Also, as you requested, an on-line tutorial.