Well, this here is a scan of the whole rules section of the latest, as of posting this, version of Warhammer 40,000. Fifth Edition.
This is a scan, as i said of *only* the rules section, so basically the first half of the book. This is only the pages you will need to play the game itself, and none of the "fluff" pages that are usually the second half of the book. Everything you need, nothing you don't.
If you know what this is already, enjoy. For those who don't, ill keep it simple. My particular favorite tabletop war game. Think chess, but with hundreds of pieces and books upon books of rules. Seems daunting, but I've been playing for 10+ years now, and I've loved every minute of it. Truly an intellectual exercise, as well as an awesome hobby to share with your friends.