Major viewing problems in different browsers

I thought I had made my website look fine. On my computer only it turns out.
I am checking it in IE6 and Opera 7. On other computers using the same
browsers I see something completely different. I am at a loss. I created it
using a css template that came with DW. I don't know what code you would need
to help me so here's my url http://www.rainbowsnails.com

I have been trying to fix it, but since I can't actually SEE the problem on my
computer I think I am making it worse.

Any help would be greatly appreciated.

Terri