Mastering Algorithms with Perl by Jon Orwant, Jarkko Hietaniemi and John Macdonald, published by O'Reilly has a chapter on graphs and graph traversal algorithms. As the title suggests, the book covers much of the standard "algorithms" repertoire with an emphasis on implementation in Perl.

Personally, I'd ask how Any experienced programmer would approach the problem, and then figure out how to do it in Perl. When learning new algorithms and concepts, it can sometimes be easier to learn things in your native human lanugage first, and in a programming language only after you understand the basic flow of the algorithm.

Alan