Keep footer at bottom of page & remove horizontal scrollbar

I’m using the Tiga theme and it was originally very boxy–separate boxes for post titles, widget titles, header, footer, comments, etc. I have set all margins to 0 and made the page background white in order to make it look like everything’s all in one big box.

But because of this I have a problem with my footer–it comes up to the middle of the page when the page is short, like on my about page: http://lollymom.com/about/

I want the center column to just be blank white space all the way down until the sidebars end and then have the footer, of course, at the bottom of the page. How can I do that with this theme? I really should have started with a theme that was closer to what I wanted, but I couldn’t find one–at least, not one that I could figure out how to customize.

Another problem I’m having is that there is a horizontal scrollbar in my archive page. http://lollymom.com/archives/

How do I make the text wrap around?

It was doing the same thing in my contact page: http://lollymom.com/contact-me/ with my text at the top, so I just separated the sentence by making a new paragraph. But that looks stupid because there’s so much space in between. I guess it looks better than the scrollbar though.

Here’s the code for my fArc archive plugin. http://wordpress.pastebin.ca/253918

I don’t know if the problem is with that or with my stylesheet. My stylesheet is here: http://wordpress.pastebin.ca/253912

Thanks so much in advance for taking the time to help a struggling novice!