It depends on what headers the web-server sends out and it also depends on what settings you have in IE. If you always want to check the page is current then go to Tools > Internet Options > General tab and in the Temporary Internet Files section click the 'Settings' button. Then make sure 'check for newer version of page' is set to 'Every visit to page'.
If I immediately "refresh" the page, should IE get the page from cache or request it from the website?
Reloading should force it to get the page from the server. However, to be sure to use CTRL-F5 to force a refresh of all page assets (images, css files, javascript etc).