A good cleaning tip to clean your microwave.:
Cut a lemon in half, then squeeze juice (lemons included)into bowl of water, about half a cup. Then put into microwave and turn on for 3 mins on high power. When stopped, leave for 5 minutes. Clean off with damp cloth and wipe with dry cloth. The results are amazing! No elbow grease involved, marks came off so easy, can vouch for that, as did mine this morning and came up like a shiny new pin!