I have found these two tools to be very useful for testing your web designs in different flavours of Internet Explorer. More often that not there will be a lot of discrepancies between versions, and you will have to decide which versions to support. I currently design websites that look good on IE6 and upwards, apart from Firefox and Google Chrome which usually do not present any problems as they are standards compliant.

http://www.my-debugbar.com/wiki/IETester/HomePage

http://tredosoft.com/Multiple_IE

A good place to get some help in getting your designs to display well on IE is Sitepoint’s forum at www.sitepoint.com/forum