First of all, my biggest tip would be to bring a carrier for the baby. My baby bjorn was a God send!!! I used it while going on rides and to just give him a break from the stroller!! I brought our Peg Perego because of how easily it folds. I was worried sometimes to just leave it behind but it was fine. At night DD got tired and fell asleep twice in the stroller!! I was happy to have the carrier for the baby.
He wasn't afraid of anything. He just starred and was so excited about the lights and stuff. Whether the baby was up or sleeping I simply told them I needed to leave him in the stroller and it was no problem anywhere we went. We have been 5 times before, so this time DH said no planning!! So we just picked a park and spent the day, usually arriving at 11am!!! DS just sleeped in the stroller.
Some tips: make sure babies head is covered, even when it was 75 degrees, the sun is very strong. Use the baby centers at the parks. They are awesome!!! Bring your own stroller.
If I think of more I'll post. As for a good spot for a Christmas picture, I can't think of anywhere right now. I will say that the decorations were up everywhere. The BW had great decorations and nice photo spots.