Jeck of Burning Blade-US made some basic PvP tutorial videos for priests. They are easy to understand and offer good tips and tricks for both seasoned players and those new to arenas/PvP.
Video 1: Mobility, terrain, priest tricks, some add-on tips
Video 2: General priest PvP advice, tricks, some add-on tips
Check out the “Useless Tricks” thread on the WoW-US Priest Forums. It contains links to his 3rd and 4th movies, as well as videos submitted by other players as well. Definitely worth checking out!