Agreed; lots of pics!! As for "clicking" at shows, when I get there I let them have a look around, eat some grass, call out to the other horses, and just take in the whole atmosphere. Then I'll tie them to the trailer to go register, and after that, I keep them with me as much as I can. Walk them over to the drinking faucet, rinse them down by the showers, and just walk them around the fairgrounds, letting them get a feel for it. When it's time to warm up, I give myself a lot of time and work on focus. Now that you've let him see everything, it's time for him to trust that nothing is worrysome and focus on listening to YOU. Keep calm and relaxed; tensing at anything will work up an already nervous horse. When it's time to do your pattern, trust in your horse and yourself that you've done everything you possibly could to prepare him for this, and that you're going out to prove it.
Good luck, and have fun!