I don't really get why people would bring their small children (3 and under) to an event like AN but then I don't have kids. I can barely navigate myself through those crowds, let alone imagine having a small child and/or their pram with me.
As for tips, I'm adding my voice to the water is good vote. I usually bring a water bottle that keeps stuff cold for hrs. Parasols/Umbrellas come in handy as portable shade if you carry one. If you're at the con in a pair or with a group, it's probably a good idea to have a designated time/place to meet up just in case. If your hotel room doesn't have a fridge, bring a cooler to keep drinks in. Snacks are always good to bring with you. If you go to Perkins, be prepared to wait a long time.
Which speaking of, anyone know of a place that's good for breakfast besides Perkins?