Whoops. Guess I'm behind the times.

Last time I went to that link, it was empty. Well, it wasn't but it only contained general help info. Granted, I think it was still back when I was beta testing 0.6.
Still, I think including a copy of that HTML file with the Calibre install would be a good idea, specially for people who occasionally need to work on ebooks when they don't have internet access. Then, just point people to that HTML file.
I also suggest switching the link in ebook-convert --help from:
http://calibre.kovidgoyal.net/user_m...onversion.html
to:
http://calibre.kovidgoyal.net/user_m...k-convert.html
At least, temporarily, while the first link is still empty.