My standard rap about the perl debugger is that it only takes around a half-an-hour of playing around to learn to use it, but you need to do this some time when you're not worrying about a bug.

Also, if you start out reading one of the standard references it's easy to get scared away by the sheer quantity of commands (there's around fifty, not counting all of the various options).

I recommend just starting with these:

• s - single step
• n - steps carefully to avoid falling into a sub
• c - continue processing until a break of some sort
• r - continue running until you do a return from the current sub
• v - view some code around the current line
• b - sets a break point (uses line number or sub name)
• x - displays value of variables (including arrays & hashes)
• w - sets a watch expression
• T - displays a stack back trace
• L - list all the breaks and watches
• B * - delete all breakpoints
• W * - delete all watch expressions
• R - restart

(I wrote a debugger tutorial once, but it's way out-of-date. There's a standard one now: perldebtut).