Lots of good regex info if you search around Perl Monks try Perlmonks Tutorial: Regular Expressions Tutorial, the Basics (for BEGINNERS)
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.
Don't forget to use a \ to escape out special characters when using regex.
Good Luck.