I do personally like "Effective programming perl" (J.N.Hall, R.Schwartz, Addison-Wesley, look up effectiveperl.com for samples or Book Reviews for reviews by arturo and jbardhan) very much. On the other hand it's at least to me always interesting to read merlyn's columns (always tricky and full of magic) and to read nodes from the past, especially in the code section or trying to read and to get module sources, but that's still hard to me. :-)

Have a nice day
All decision is left to your taste