I have 150 rounds through my Bushmaster M4A3 and have yet to do any cleaning at all in the guts, when should I start and what parts should I focus on the most?

Cleaning your rifle links

the trigger area I would not worry about,it should still be clean.the bolt assembly, where it rides and the barrel.clean that up.at least to see any problems that may be there.I doubt you will find any.shoot and repeat.

Listen if your in combat and cant clean it it will run dirty as long as its lubed.In civilian life get in the habit of cleaning it when ever you use it.After you run 2 or 3 thousand rounds through it will be as smnoothe as glass in its operation.I never tortutre test my ARs or leave them dirty because I figure after 40 years of service I cant do anything to it the Army and Marines have not already donr to that rifle by accident or purposely.Clean it weather 10 rounds or 500.Cleaner runs smoother.

Being this is my first AR and gun for that matter, I dont know anything when it comes to cleaning it, what i usally do is spray CLP in the holes of the bolt car, and whipe down the inside with a black rag and some CLP, is this good enough?

BORESNAKE for the barrel.there everywhere.

Love my BORESNAKE...