What is the best way to build a lemonade stand?

My son is going to build a lemonade stand(with help). What is the best way? He would like to make a ply-wood box that opens on one side as a storage space. He would also like to add wheels and a nice large sign.
His sister would also like to make an add-on bead-jewelry stand on the side.
If you have some extra ply-wood what is the best tool to use? Also should you use nails or screws.And we need to buy Hinges, handles, and wheels(turning wheels) for it. Where could we get those? There is a Home Depot and Lowes near by, could one of those be of help?
What would be the best way to present a sign. They want thier primary sign in the air supported by the stand but is it best to have a cardboard(white or brown), paper(any color easy to get at stores) or should we paint on wood? What color sign and color text should we use?

WELL? do you have tv trays. cuzzz it works PERFECTLY!!! pluse you can put a sign on it saying LEMONADE :>>>>! Well if thats a badd idea then use wood???