Some cleaning tips...
A copy from Amana:
What kind of cookware can I use on a glass smoothtop?
Amana does not endorse any particular cookware brand for use on a smoothtop. We do not recommend using any glass, glass-ceramic, enamel-porcelain coated, or cast iron cookware. Small imperfections on the bottom of such cookware can scratch the smoothtop surface. While the surface is not scratch-proof, it is highly scratch and impact resistant. With proper cooking utensils and care, it will continue looking good through years of use.
The cookwares bottom diameter should closely match the size of the heating element or burner area for the best cooking efficiency. Pots and pans that are too large (extending more than one inch over the sides) may cause cooking times to increase. Pots and pans that are much smaller will result in energy loss and could increase the potential for accidents.
We recommend using heavy-gauge metal cookware that has a smooth, flat bottom. The flatter the bottom surface, the better it will receive heat from the element and conduct heat to the food. Cookware that is warped or curved on the bottom will result in slow heat-up times and may not even boil water. Many brands feature cookware with an aluminum disk on the bottom, which makes good contact with the cooking surface.
To verify if a pan has an absolutely flat bottom, take a ruler with you to the store when you shop. Follow these steps:
Place a ruler along the bottom of the pan.
Rotate the straight edge a full 360o around the bottom of the pan.
Check for flatness in all directions.
If you see light or a gap between the ruler and the pan bottom, the pan will not cook efficiently.