like moonweasel said, don't be afraid to climb the lower numbered courses for awhile.
One thing I learned quick when climbing was using my legs to push myself to the next hold rather then my arms to pull me. Think of your arms/hands in most cases as an anchor. Bent arms also fatigue quicker then straight arms when holding.
oh, and treat your hands well after a long day of chalking them! My hands started splitting after a couple weeks because I wasn't using anything after my climbs to moisturize my skin.. looked pretty nasty..
dammit, now I want to climb again