The German fan site HellgateLondon.de seems to have a good classes section, including many player-created class guides but... it's in German. You can try running it through Google, Babelfish etc. lang. translation tools:http://www.hellgatelondon.de/klassen/klassen.php
There's a budding Hellgate Wiki at:http://hellgate.wikia.com/wiki/Category:Fansites
Though not a whole lot listed just yet.