I've already say that somewhere else, but...
I think the best way to start with theming is to begin small:
- take a look at http://ls-ots.cjb.net/ to see what you need, to make an OTS compliant theme.
- run an explorer instance and kill litestep.
- rename its folder.
- make a new Litestep Dir with only the lastest Indiestep build into it.
- start writing your step.rc

Begin small:

ModulesDir "$ThemeDir$Modules\"

LoadModule "$LitestepDir$desktop2.dll"
or
LoadModule "$ModulesDir$jdesk.dll"

LoadModule "$LitestepDir$hotkey.dll"
LoadModule "$LitestepDir$popup2.dll"

*Hotkey WIN E explorer "$LitestepDir$"
*Hotkey WIN S notepad "$ThemeDir$step.rc"
*Hotkey WIN R !Run

That's the minimum... after that, you'll have to find what you really want to do with Litestep (it could take years)...
If you have special questions; we are here !

Have fun!