Hi MATTXtwo,
Welcome to the incredibly annoying world of developing websites across multiple browsers!
The problem is that IE does not follow the rules of mark up correctly unlike other browsers such as FireFox and Opera which do. This is why when you develop your site in IE it can sometimes look different in these other browsers. The thing to remember is that you should get it looking as you want in a browser other than IE because that means your mark up is more likely to be correct. You can check that your html is correct by using the w3 markup validator -
http://validator.w3.org/.
If your page looks correct in FireFox or Opera and not in IE then that is because of bugs in IE - check out
this for details and workarounds of these.
If you have any specific problems with any of this then I suggest that you post your markup and details of the problem in the HTML/CSS Forum where the experts are familiar with these issues.
Hope this helps,
Dr B