I have used a meal planner for the last two years now it was one of the things I put in place when we became a single parent family. I find them fantastic is saves time both at home and in the supermarket cause you have a list to stick to already per planned. Stress more worrying what's for tea ?? And money you have less waist an you no longer wonder round picking up anything you fancy from the shelves.
Meal planning can be done with the whole family, when I did it with my children they each day a set day they choose the tea. This is a great sayid getting them involved in chores and helping them make choices about their food. As well as reducing the fights "I don't Like that".
Net mum has some fab ideas for a starting point http://www.netmums.com/family-food/guide-to-cooking-on-a-budget/budget-meal-planner
If you shop online you can also save the food you regularly purchase which saves you even more time.