I use baking soda and water to clean mine. It doesn't scratch. A word of caution though: My stove is 12 years old and needs replaced soon. I used to use the special cleaner from the appliance store, but I switched to baking soda a few years ago without any scratches. I'd do a very small section to test it first.
Use either Weiman's cream Stove Top cleaner or Cerama Bryte. Both work well. A container will last you a really long time, even if you use it every day. A little goes a long way.
Here ya go! What other Hometalkers did.