Well there are tons of sites...but, to my opinion, the best one is this one.
If you search for topics about these watches you will get far more information than what you'll gather from the web.
We have incredible specialists like Freddy333, RepAustria, Tribal, Edge, ...and of course our main masters, Nanuq, By_tor, Ubi, Pug, ...or BKLM1234, L-Dizzle, ...
Sorry guys, I cannot name you all.
I could give you obvious links like http://www.vintagesubmariner.com/vintagesubs.html but it will not teach you as much as our members can...
My only opinion though.
Cheers
Stephane