I do this, on usually a bi-weekly basis.
DH gets paid every other Wednesday, and the sales circulars for the grocery stores also come out on Wednesdays. So when I browse the flyers, I plan out recipes based on what's on sale that week. Once I have done the major shopping for the two week's time period, I just have to go every three or four days for milk, fresh veg, etc. DH takes leftovers from meals for his lunches at work, so we save money because he doesn't have to purchase lunch.
Like a PP, I tend to keep a well-stocked freezer and pantry, so that makes it easier too.
I have been cooking for my family long enough to know how we will eat on certain nights of the week too. Friday night is "casual night" - we either eat leftovers or just have soup and sandwiches, etc. DH doesn't need a lunch the next day, and by that time, I need to clean out the fridge. The nights I am at work (Monday, Wednesday, and Saturday) DH has to cook, and while he doesn't mind cooking, he's usually quite tired from a 10-12 hr day at work, so I try to make it as easy on him as possible. I either plan things that can go in the crockpot, or I throw something in the oven that can cook for a long time and DD17 can keep an eye on it until he gets home - roasted chicken and baked potatoes, etc. Also, when I make homemade spaghetti sauce, I always make extra, and freeze it. Then DH can just defrost the sauce at a later date and boil up some noodles.
Saturday nights are often "fish nights". DH and the kids love fish - halibut, salmon, etc - me, not so much. I have tried, but I just don't care for it. I am usually at work that night, and DH has had the day off, so he cooks it for them. This also works well because he doesn't like to take leftover fish to work for lunch - he doesn't think it reheats well, and it makes the lunchroom "stinky". He doesn't work on Sundays so Saturday's meal doesn't have to be lunch the next day.
I think the keys to planning meals out ahead of time are organization, shopping the flyers, having recipes that are tried-and-true, making extra and freezing, keeping a well stocked pantry and fridge, etc. That doesn't mean that some days I don't wake up and just not FEEL like pot roast, so I swap it out for taco night. That just means that the pot roast still gets used, on the night where tacos used to be.
It helps me keep the budget down and helps DH and DD17 on nights when I am not home!