I think this article is an excellent *stub* for the theme:-). "Part one" sounds very encouraging though.
I'd be pleased to see a much bigger (and preferably categorized) list of common beginner's pitfalls. It would be only fare to point novice Perl developers to such list *before* they even start developing (maybe it'd force some not to start with Perl at all afterwords; but it's fair, isnt' it?..:-)). It's hard to overestimate a value of such a list, if it were comprehensive and systematical.
Please don't misinterpret me: although i don't normally use Perl for developing and it usually makes me very unhappy, I am not trying to start yet another "Horses Vs. Cows" war here:). My point is: all beginners make and will make tons of same mistakes; people should know what they are about to face and be aware that learning Perl to a dergee of not making these mistakes anymore is a comparatively big learning curve.
Out of the three mistakes described here in the article, I think only 1st one really belongs to the "Common *Perl* mistakes" category.
2) Repetition without Abstraction: it's a generic ugly coding practice problem; I don't see what it has to do with Perl. I mean, people who write like this will write like this in any language; and vice versa: people who don't in other langauage, won't in Perl either.
3) is common sense.
On the web, I also often see Perl idioms / general good practices mixed with "beginner's mistakes". Things like "Use "open or die" instead of "open"", "don't forget to print Content-type..." and xillions of others that have nothing to do with Perl.
But enough philosophyzing. I will now add a couple examples -- things that I stepped onto in my own practice -- as separate posts. That is, if I'm not moderated out of here...:-)