Where is the docs for the project?

[basharov]

I can't find any documentation for the project, does it exist at all or should I understand how it works by digging in the code?

[lego12239]

A some kind of a tutorial or a guide is not a strong aspect of mochiweb :-).
Try to see:
http://alexmarandon.com/articles/mochiweb_tutorial/
make edoc