Need some help editing a theme

I would really really appreciate it if someone who knows how to mod themes would give me a hand. I almost have it finished how I want, but there are some additional mods I would like to make to the theme.

Also, Is there a way I can add custom fields to the “Write” thing? Like if I know every entry will contain a certain thing, and I want to put a field in.

AIM= DHermit202
E-mail = matt (at) dhermit (dot) com