Here is a great recipe. It is not very sweet, but it has a great texture.
2 oz. dried yeast
5 cups water
½ cup sugar
3 eggs
½ cup oil
3 tbl salt
5 lbs flour
The recipe will make 6 lg challahs. I would bake at 350 from 35 to 45 minutes, depending on the size of the challah. The best way to check if and when it is done is to tap the challah by flicking your fingers at the top and if it's done you should get a hollow sound. Good luck!