For us, the photographer (aside from the DJ at the reception) drove the whole thing. He told us how things would go down... even how to hold the ring when we're about to put it on the spouse's finger. Your photographer should be there with you prompting what should go on. Don't settle for anyone who's more laid back or standing in the shadows. He and the video guy are the two people who are responsible for your memories after it's all over (what else will you have left after the event is over right?) so he has to get the best shots and be the one in charge. Look for that quality and make sure he's got a lot of experience already. He should be the one asking you a lot of questions (before the day and during).
Other than that, question the amount of hours he'll be with you. We had to pay 1.5 hours overtime so he would get the bouquet throwing toward the end. He started with us at 10am and didn't end till 1130pm. We finished at midnight. Mucho importanto.
As for the bakery, make sure everything is written down on the contract. Our guys delivered the cake and decorated it, but they neglected to decorate the table too, which was on the contract. We have to go yell at them about that.