DD had a magic school bus party for her 4th b-day and we got school bus stickers from oriental trading company which we put a few in goodie bags and also gave as prizes for games. I also got a school bus craft from there, very easy that 2 year olds could do. I made yellow bus shaped bean bags which we used for bean bag toss and I gave one to each child in the goodie bag. They were very easy to make and I'm not all that crafty. Yellow balloons. Yellow plates and napkins. School bus coloring pictures. I got fisher price school buses (I had one and borrowed a few from a friend) and put the cutlery in one, put the crayons in one.
That's all I can remember for now, if I think of anything else I'll let you know.