Just been snooping round on Apologist's advice and found the Adeptus Mechanicus Codex they have developped there. It is well worth a read (you'll also start to understand when Apologist starts talking about Warnings, etc... ;)).
I believe you'll have to join to look at it, but it didn't cost me anything and they have some great resources and their events look rather good.
Tempus FugitivesBy the way, the codex is in the Forum, under the Mechanicus section... Took me a while trawling through their downloads and searchy option to find it...