an assortment of brushes in various sizes to clean your gun with., I use lacquer thinner as a solvent to clean my gun with.
definately get an air line drier. i use one that mounts to the wall about 8 ft from my compressor. i need another one at the terminal end of my air line too.....
a paint gun stand is real handy. my paint guy wanted way more than i thought it was worth so i made my own out of scrap i had laying around...
and DO NOT let your gun dry with catalyzed paint in it as that will make it a booger to clean. (can we say booger on this site?)
good luck, i'm about ready to lay my paint too, well see how it turns out.