JC,
That you are nervous tells me you are already way ahead of the game. Our first comp was the very first Roc City, which was ribs only. We rolled in without a care in the world - because we didn't know any better. Had we actually done some homework, as you have, we would have known we should have been a little nervous.
We have a few more comps under our belts now, and for what it's worth, here's a few things we have learned along the way:
1) plan your cook and cook your plan. Prep a timeline for your cook from beginning to end and stick with it;
2) Know that no matter how well you plan or how many contingencies you have in place, something is going to happen you didn't see coming - the temp dropping 20 degrees when the rain comes in, the small grease fire in your cooker when you are trying to finish chicken, etc. The best brisket we ever cooked came after our overnight cook was over-served and passed out and the fire went out. Stuff happens, but how you adapt and overcome is part of the fun;
3) make sure you stop once in a while and look around so you don't let the experience pass you by. Whenever I do I am always struck by how wonderfully absurd the whole thing is and it reminds me that first and foremost it is I about having fun with a bunch of fellow BBQ nuts.
Stop by and say hi at Roc City. We'll be in the back corner, actively adding to the aforementioned wonderful absurdity.