Definitely learn to use version control of some sort (I'm still stuck on Subversion) as early as you possibly can. Indeed, it'll be great to track your progress as you build up code on more complex stuff. Also, you'll definitely be great in a team environment and it'll foster a somewhat safer team environment, too. Teaching a developer now at my job (who was in place before I was) how to use SVN because now we're officially a team and I stay nervous about accidentally hosing anything he does or vice versa.

And yes, being able to rollback bugs or things your users don't like in a systematic, traceable way is absolutely the best. Undo only works up to a point lol.

Check out The Pragmatic Programmer for more nice ideas about being a developer. http://www.pragprog.com/the-pragmatic-programmer