AR15dotcom can be a bit overwhelming at first.
I say just follow the owner's manual, take it down, pull the bolt and firing pin, clean it, reassemble, repeat, then lube it up pretty well. Practice with an empty mag, lock the bolt back, release the bolt, set the safety, dry fire it, etc....just get a real feel for the controls before you go live. You will realize they are pretty darn simple.
I can't recommend any particular book or video, but I'll bet if you punch in the right stuff on youtube you will get a ton of hits.
Hit the range and shoot it. Be safe! Know and 100% obey the gun safety rules.