IE is commonly known as the most problematic browser in terms of consistent look and feel. What are the most important IE rendering 'bugs'?
Version specific things are fine, just mention that its version specific.
EDIT: partial duplicate
The worst mistake a developer can make is not using a doctype. This sends IE into "quirks mode" where it uses a different box model and has many other problems. This is simple to fix, you can even use the HTML5 doctype to trigger standards mode:
The second major bug is the double-margin float bug. When you float any element and apply a margin, it is doubled in IE6. You can fix that by adding
display: inline to that element's CSS.
(Note: This question may be better asked - or already have been asked - on Stack Overflow.)
This seems like a fairly complete list:
I wrote an article a few months ago for common IE6 bugs: Ultimate IE6 Cheatsheet: How To Fix 25+ Internet Explorer 6 Bugs. It'll help for some IE7-specific bugs as well. There are more resources at the bottom if you need them.