Robert, there are a some Brothers that have extensive competition experience and they can probably better answer you than I can, but as somebody just a bit ahead of you having already considered a lot of these questions I'll give you my $.02 worth.
Organize your gear so you have everything you need and nothing you don't. Space is limited so plan carefully. There are some checklists floating around the group. Practice cooking out of the boxes or containers you're going to transport you gear in. If you have to go to the kitchen for something, edit your checklist on the spot.
Timing seems to be one of the biggest things to consider so work out what stuff you're going to cook in what cooker and get a solid time line down for each cooker you're running. You don't want to turn in under cooked stuff obviously but what's great for eating at home can be considered "overdone" and not score well. When establishing your time line do a full practice, one cooker at a time. My plan includes brisket followed by BB's in my cimarron, the ribs will cook considerably different alone than they will with 2 wrapped packers in the belly so I practice ribs with wrapped packers in the bottom.
What woods, rubs and sauces to use is good cooking sense with a huge dose of crap shoot involved. Consider the area you're cooking in, if local Q joints serve vinegar heavy sauces it's likely the local judges have a taste for it, then again you could get a group of judges that hate vinegar, so you take your best shot.
What to cook will be dictated by the sanctioning body or local rules. KCBS is Chicken (thighs are what's in now),pork ribs (spares or loin backs, loin backs), pork shoulder and brisket.
Follow the basic Brethren methods and techniques, add your own "flavor" and have fun, thats the one thing you can do everytime.
