[SOLVED] Adding borders to sides of blog with blog centred in middle of page

Hello,

I've searched these forums to find this answer and can't figure out how to do this. I want to make my blog 2 columns, with the center and right hand sidebars and have them centred on the page with borders on either side of the blog. There's a member of this forum who's blog has exactly what I mean, so I'll post a link to it:

http://www.cometomachupicchu.com/blog/

If anyone can help me with the code I'd appreciate it.

Thanks,
Rhymes