Is there any doc on the creation of Modules for LiteStep?

And in particular using .Net (c#)?

You'll find links to some tutorials on litestep.info, although you won't find anything on c# afaik, as most modules are coded in c/c++.

If you need any help/information feel free to ask in #litestep and #lsdev on irc.freenode.net.

There are also some tutorials at shell-shocked.org.
That and lookin at some module's source should help. So should the LSSDK, somewhere in source forge, i think.
In what pertains to C#, that's a whole different story.. But as long as it interfaces nicely with C, there shouldn't be any problems using it, say I.

http://www.shellfront.org/modules/source/