New to 556 and to rifles in general

Hi all. This is a GREAT resource and I've been reading so many posts. I'm in Colorado and purchased my first "real" rifle just a couple weeks ago - a 556 DMR. I have a LOT to learn, and know I'll get many answers from reading existing posts. If I could be so bold as to ask if there's some kind of good intro on how to actually hold and adjust the rifle somewhere? I don't want a sniper's manual or anything, just some pointers on how to adjust the adjustable stock for best performance. I have the Magpul stock on my DMR.

Thanks,
Jim