I was in exactly the same boat a few weeks ago with a group of players who hadn't got a clue about the world. To get them into the game quickly, I gave a brief overview of the mechanics, told them that they were playing in a dirtier, more dangerous version of medieval Europe, then played A Day Late... with them with them using pregenerated characters. They were surprised by and scared of everything they met - which admittedly, was only beastmen - because they didn't know what kind of things could happen to them. At the end of the session, the setting had already got to them, and they were all promising to go out and find out more about the world themselves. I told them a little about it and they felt equally appalled and excited by the fact that it felt like humanity was being attacked on all fronts. So although their characters would know all about beastmen, for this starter/taster adventurer, I felt that it was more important for the players to get a feel for the game and the dangers rather than get too bogged down with the rich - or should that be filthy, poor and violent - history. When we start to play Eye... they'll have lots more background (thanks to their research and me sending them stuff like scans from the book) to create their characters. They're hooked on the game, and to me, that was the first obstacle to overcome. It means they'll appreciate all the flavour stuff a lot more now which I can start feeding to them slowly but surely. So in short, get them playing first! Even shorter, what mordjinn said.