When improving my coding ability in Perl I have found the following to be useful. (These same ideas have worked with other languages as well.)
- Read the book - you have several good recommendations already - but look to answer specific questions. Use it as a research tool. I always use a good old-fashioned book. (I guess that I'm old-fashioned myself.) It is often more helpful to get away from the screen/keyboard/mouse and relax a bit while you look something up. but...
- Keep perldoc bookmarked in your browser - there's no better way to quickly find the exact syntax that you want.
- Look at other's code; you don't have to do things the way they did, but seeing the way someone else successfully solved a problem will show you possibilities that you never thought of. Perlmonks is one of my favorite sites for this; I have learned a lot here, including new approaches to problems that were big improvements over doing things the way that I had been.
- Google is your friend.
Good luck and have fun.