I'm pretty terrible, so I figure learning and playing some theory will help me out.

I'm self taught, and I skipped chords and all that stuff and went straight to tabs/power chords and stuff like that.

Also, I know absolutely nothing about theory.

The lessons/columns here on UG are pretty good, as is www.justinguitar.com.
Quote by Geldin
Junior's usually at least a little terse, but he knows his stuff. I've always read his posts in a grouchy grandfather voice, a grouchy grandfather with a huge stiffy for alternate picking.
Besides that, he's right this time. As usual.
I thought I "learned" theory online (here and other sites). I thought I had it down. Then I took a real class at a local community college and my musical life changed. 101% worth it, especially since there was credit involved ^.^

But for a start, learn some basic chords and scales. And then some less-basic chords and scales And +1 to justinguitar.com for that.
-Agile Interceptor Pro 7-string
-PRS SE Standard

-Bugera 6262 2x12 combo
-B-52 AT-100

Pedals (rarely used):
-Digitech Whammy
-BBE Green Screamer OD
-Morley Bad Horsie 2 wah

Home made cabinets and cables