I plan my meals out 2 weeks in advance and it works wonders! I've saved over $50-$100 a week planning that way. We all sit down around Wednesday/Thursday and plan so that I know what I need for meals and go shopping on Friday.
Here was my meal plan for this week (we are in week 2 and sorry, I don't know where my list is from last week to show you!)
Friday - Chinese!
Sat - Hamburgers/hotdogs, baked beans, corn on the cob (burgers I premake by buying meat on sale and pattying them up and seasoning them and then individually wrapping them to have later...throw them on the grill frozen..we are good to go.)
Sun - Long story, dinner got canceled and I had to get pizza (cheap $5 pizzas)...my dishwasher broke and I was under it trying to fix it. It works now, but, dinner was out of the question. David wasn't home. GRRRRR.
Monday - Crockpot Cream of Mushroom Chicken over rice with broccoli
Tuesday - Left over night
Wednesday - Chicken casserole, peas (I have a great CHEAP recipe for this)
Thursday - Crockpot Chicken quesidillas, refried beans, spanish rice
Friday - Spaghetti night, garlic bread, salad
We normally shake things up a bit...but, we happened to have A LOT of chicken this week. I'm getting chickened out.

The kids LOVE mexican...so, we either have chicken quesidillas or tacos each week. A pasta night (spaghetti or tortillini), a hamburger night, whether it's mamwich, meatloaf or burgers, etc.
I guess you get the idea. I buy a lot of things with coupons and when they go on sale or I buy generic and add seasonings myself to make them better (ie: spaghetti sauces).