Hacking Away: 3 Column CSS Mess

Questions. Problems. Help?
Try not to laugh at how mangled my site is at the moment. This is a work in progress. I’ve been trying to learn a lot on my own, but there’s only so many hours in a day.
The left column displays posts in the “normal” manner. I’ve hacked up index.php to give me the latest excerpts from one category in the center column. The third column is for everything else.
Current burning question: When clicking the links to posts, they appear in the left column. This is silly when I click on a post from the center column and it appears to the left of it. I’d like, instead, for the full posts to appear in a new layout, likely a two column design (basically, the site without the center column). I have no idea how to do this.
I’ve been searching for a post that showed only the “comments” page when you clicked on the post link. That might help me, even though I’m going to be using forums instead of comments, I could use the comment CSS styles for this cleaner design.
I know this site has a LONG way to go. I’ve gone about making 3 columns all wrong. I’ve given Dots and Trident a shot, but neither worked for me. My dream of liquid columns is probably foolhardy. My footer is out of whack, the columns bleed into one another and extend beyond their divs, and the #rap doesn’t talk to me anymore. Probably best not to even mention yet the differences in IE vs. Firefox displays.
I tried. Um, anybody up for some hand-holding?