I've been playing ES for a long time now, but recently have convinced a couple friends to give it a go, one of the first questions they asked was where they could go to find a website showing the different ship looks for each faction/class? I checked the ES Wiki but had no luck and a short hunt on Google gave no real decent results so I was hoping someone here could help me point them in the right direction?

What about showing them the digital artbook?

hmmm, they are still in the wiki, on the pages for the ship classes: http://endlessspace.wikia.com/wiki/Cruiser#comm-6788

those however lack the Harmony, Vaulter and Sheredyn ships, and most Fighters/Bombers, also the Sower and Automaton Transports.