The first things my mom started me out on for using the oven was something glamorous like French Fries - just heating them up. I now use my oven mostly for baking - cornbread, cookies, bread, cakes, muffins. For meal-type things, I make lasagna, a noodle/veggie casserole (I found that recipe in Vegetarian Times Low Fat and Fast) and other casseroles, baking squash, quiche, baked potatoes, etc. It seems so obvious to me, but if you really haven't used the oven all that much, it might be worth it to say that using the oven buys you time right before dinner - you mix something up, put it in the oven, and then wait. If you're short on time (or short on patience), the oven probably isn't going to be that useful for you, because you simply have to wait.