Well, I don't think it's cheating, unless you're taking some kind of a test that requires you to work without any help other than your eyes and hands.
2) My ideas about this subject
3) Some examples from the past of artists who have used grids
4) A free grid program for your computer
5) Links (where to buy a grid device; where to buy canvas already printed with grid lines; how to use a grid; how to make a very simple perspective device.)