This placed in the head section will do the trick...
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
Also, adding this line as well will make it more reliable. Netscape will let you avoid using the cached page but IE has some problems cancelling the page cache. From what I've read, these meta tags don't work too reliably as IE ignores them. If you use Active Server Pages or some other type of server scripting you can set the header information there, which will work on all browsers.