Like I've said in previous posts there's lots of good regex info if you search around Perl Monks try Perlmonks Tutorial:
Regular Expressions Tutorial, the Basics (for BEGINNERS)
It helps if you try to code something up yourself then post. I've found learning by doing is the best way to get familiar with REGEX.
I have also found http://www.regular-expressions.info/quickstart.html very helpful working with regex's. Lots of good examples.
I found tools like http://www.txt2re.com/ or Eclipses regex tool to be helpful in debugging my regex commands.
Good Luck.