What's the best way to learn the fundaments of shooting an AR-15 and also what is a good way to ensure that I don't develop any bad habits? I've been to the range a few times now and when i'm shooting i'm just constantly thinking to myself if i'm doing this right, or doing that right, etc. and really just have no idea if i'm doing something the wrong way or not and it's frustrating. I have no access to any NRA instructors or anything like that, so i've got to learn all this on my own. Ideally, I would like to show up to boot camp already being able to shoot expert and not have any bad habits that I developed on my own. Any good books or anything I should buy?