UX Rule #1 - All HTML Form Control Elements Require Labels (forfraksake.com)

http://www.htmldog.com/ has a lot of great info on how to build good forms. It's a good resource for things like this.

I feel embarrassed to say that I didn't actually realize that labels automatically associated with form elements such that you could click on them...

I usually used labels anyway, but mainly because they were semantically correct.