Graphics colors are a bit hard on my eyes. I prefer more contrast. Text stands out well in most cases which is the important thing.

Looking at your source, you have way to many repeats of the same words in keywords. For example, "fix-it" is repeated several times as a stand alone word. This is as opposed to having "fix-it" and "fix-it stuff" which the SE see as two different but related words. You might be penalized for spam for the repetitions. You might also want to add some keywords and phrases with "fix it" without the dash. i.e. "fix-it,fix-it stuff, fix it, fix-it stuff" would be considered four relevant but not duplicated keywords/phrases. Home repairs, computer repairs, are others you might want to look at.

I like that you let people look at the forums before registering. I hung around a few minutes and checked some out. I didn't try to reply but even if you have to register to reply (which I would require in your case since you obviously have a lot of posters); you've still given a casual surfer enough info to hook em into signing up.

I would add the following to the header:
<meta name="robots" content="index,follow">
Some say it isn't necessary, I don't argue one way or another but I include it in my pages just in case it helps even a little bit.

There's another discussion elsewhere here about relative vs fixed links. I believe the general outlook is that fixed is preferable. I use them and they seem to work for the bots.

JohnF