My best advice is to come up with 4-5 easy meals that you know that your kids will eat, and just serve them on the same day every week.
For example:
Monday - fresh fruit, fresh veggies, hummus, olives, pita bread
Tuesday - quesadillas, canned refried beans, fresh fruit
Wednesday - canned soup (I like Amy's), salad in a bag, loaf of bread
Thursday - rotisserie chicken, steamed veggies in a bag, microwaved rice
Friday - Amy's pizza, raw veggies and ranch dip
It sounds like it will get old, but surprisingly, it really doesn't. And it frees up your mind for so many other things.