Lets be honest, building a UAV is never going to be an easy project. Perhaps if you were copying a proven design it would speed up the process. There are several UAV specific forum sites, at least one based on Arduino controller(s), but I don't have a link handy.
I've been in radio control hobby on and off for most my life and have enjoyed electric powered aircraft and indoor heli, but I would not attempt to take on a UAV project, I just don't have the space for proper and safe testing. I have seen some very impressive UAVs on U-tube, so it can be done. Not trying to discourage you but taking on a UAV project will be a pretty expensive and time consuming project with lots of setbacks before finished I suspect.
Lefty