In IIS 7 you have much more control over the configuration and settings. It is very granular and allows you to tailor how a site or web application functions. I love this aspect of IIS. One difficult problem to overcome is just the sheer number of things you can configure. I now have my primary web host set to the very basic elements and schema I prefer. To get to this point I had to read and understand what each element does.
Here is a great reference link / Site to help answer any IIS 7 configuration questions. It includes the reference, code samples, examples, and any IIS 6 information.
http://www.iis.net/configreference (LINK)