Someone said to watch as much hoop as possible, but I would be cautious about watching too much NBA. That is where alot of misconceptions are formed by fans. Also, forget terms that are used by Billy Packer or turn down the volume when he is talking
Be sure that you control the things that you have direct control over. Work on your signals, strong signals can go along way in gaining credibility with partners, coaches, and assignors. Understand the rules inside and out. Hustle and look the part. Find a mentor and go to camps for additional training. The rest comes from getting as much experience as possible (working games).
Oh yea, one last thing, don't say "yea, but,...."
Good luck!