These pages contain a web-based course in typing mathematics using LaTeX.
I have uploaded some html "help files" on LaTeX and kin, obtained from the usual CTAN site http://www.tex.ac.uk/ where plenty more information on LaTeX is available. The help files here are not completely comprehensive nor very up-to-date, but they may be useful, especially if external websites are not available. You'll find much more (and probably much more up-to-date) help on the web using google. For my copies of these help files, jump to:
You may find other similar help files available. (For example, mikTeX comes with one such in windows help format.)