If you don't mind a non player chiming in, you might find this useful<br/><br/>Warhammer 40K Fluff Bible (http://www.scribd.com/doc/7027523/Warhammer-40K-Fluff-Bible#key1qahs08oel8qajmdcdxg)<br/><br/>It's the 40k fluff bible, which is a collection of assorted pieces of flavour text and information from many years of offical GW publications. Now, it may be somewhat outdated .. I first came across it years ago .. but for those unfamiliar with the 40k universe it should provide a decent wealth of details, and a reasonable overview.