So, if you're like me, one of the few things about 30k that's frustrating is how many books your rules are spread across. Even if you're playing a single legion, you need
AT LEAST the crusade army book and the legions book or book vi for the newer legions. If you're also using an army with a different detachment, now it's like 3 or 4 books. Forget that! I always copy my relevant rules and stick them in a small 3-ring binder so I can have exactly the information I need with minimal flipping around.
If you're like me and you like to do the same, well, here's the cover I made for the binder for my army and my brother's alpha legion force. Feel free to use these or get inspired to make your own!
These are by no means 'professional' looking, but they were fast to make and they help you easily identify which binder is which when you have a stack of 'em!