One way to get exposure to a good range of problems at all levels is to hang out here. For questions that look like something that you may be able to handle, have a go. Not with providing an answer here as to immediate goal, but just as a exercise in solving problems and writing solutions to those problems. If you want your answer "marked", post it as an answer, perhaps with a caveat depending on your comfort level. Even if you don't post an answer, you can at least see what other people have posted and compare your approach to theirs.

Perl has a lot of power hidden away in the corners, but it is generally a fairly forgiving language. If you want to post code here and have it critiqued, go for it. Questions go here (SOPW). Requests for comments might better go in the Meditations section. In general small self contained scripts will be better accepted than larger scripts or scripts that depend on external resources such as files or databases (CPAN modules are of course ok).

Update: clarify "external resources" - thanks hippo