Styling Forms

Does anyone have a good (simple) tutorial for styling forms? I have found in a couple of the events/schedule related plugins I’ve tested that the forms are (purposely) unstyled, but in my google searching, I realize it might be a little over my head since I don’t know css.

I’m not looking for anything flashy in a form. I just want something plain, while also not looking like it’s a form from the 1990’s (how it looks right now) Could anyone perhaps point me in the direction of beginner guide or a site that has sample code for toying with css for forms?

Thanks,

Sel