I recently upgraded my Moveable Type from 3.2 to 4.1 and am having major problems finding documentation on the templates. I need a real beginners guide to just installing one of the available ones through the Stylecatcher link on the System Overview tab.
Once I select one I like, how do I impliment it?

Here's how you do this:
1) Go to Design->Templates. 2) Click on "refresh blog templates." This will delete your existing templates and install the new 4.1/4.21 templates. You can back up your old ones if you want, but none of the new styles will work with 3.2 template markup data. 3) Go to StyleCatcher, select the style you want, apply it. 4) Rebuild your blog.
For future references, StyleCatcher does not install templates, it installs and configures styles. These are just CSS stylesheets and images. Templates are files/database entries that generate the HTML for your blog.
Btw, if you are in need of some new styles, I have converted over a large number here. Just unzip any of those zip files into mt/mt-static/themes and you'll be good to go for having them in StyleCatcher. I'd give you my repository URL, but right now I'm fighting a bug in StyleCatcher that prevents some of the images from being pulled correctly.