Also if the guy your working with knows his stuff than let him do his job. Just sit back and take notes on everything. There is a ton of stuff to learn and if you dont know much you can actually mess things up by not listening to the expert.
Things you should learn on the art/pre production end
halftones, halftone shapes, angles, dot gain
dif types of separations/prints
4-clr process, simulated process, index, duotone, spot
general color theory knowledge
trapping & choking
using overprints
solid underbase v/s halftone underbase
minimal requirements for elements such as line width, font point size
How colors are effected with underbase and without
this will keep you busy for quite a while
