[Where do I go from there?]

I've downloaded others themes, and even modified theme a little, but I want to really get into it...

I want to make my own theme from scratch (basing it on Window's Aero).

My first goal was to simply remove the user account picture on the start menu, and move the places listings upwards (close the gape), and I have successfully done this!! Here is my testing desktop

Where do I go from there?
I've exported 'all' to a StyleHack file, which creates a .msstyles file. What is the difference between a .msstyles file and a .theme file?

I would like the ability to install it like other themes, where it shows up in the Control Panel theme manager and doesn't go away every time I restart or change themes.

I cant find ANY information on how to do this, please help.