Yes, that's a very popular idea around here; we used to do one a month. What we found is that most restaurants have a way in mind already of how they want to do it. Here are some of the options we've had: 1) over a period of a few hours, we get a percentage of all sales that walk in the door, 2) for a full day, we get a percentage of the sales from people who bring in a special flier, 3) the restaurant looks at the average sales for the last few weeks of the night we want the event (say a Wednesday night, so they'll look at the last month of Wednesdays), and give us a percentage of the sales over that average on the night we go, 4) they give us a flat fee for the night, 5) we collect receipts from anyone who goes to that restaurant over a week or month, and when we turn them in we get a percentage of the food sales for those receipts turned in (but it has to be the guest receipt, where they see the itemized food bill, not just the credit card slip). There are probably a few variations I'm not remembering.
If people have to turn in a flier for you to get credit, the restaurants usually won't let you hand fliers out to people once they get there. They may let you hand them out in the parking lot.
Also, sometimes they will provide signage for you to remind people about your cause. Or they may give you access to a face painter. Or you can ask to bring in a face painter of your own for the night.
Bottom line of most important things I've learned:
1) It's a better deal for the restaurant than it is for you.
2) You have to publicize it a lot so people don't forget, but other than that, it's not very labor intensive.
3) Getting people to remember to bring in a flier is difficult.
4) I suppose this depends on the demographics of your school, but high end restaurants don't work out well for something like this.
5) McDonald's is always our most well attended restaurant night. Because it's fast, cheap, and Ronald McDonald comes out and plays with the kids and poses for photos. We are in a Title I school, but still some parents will come and at least get their kid a Happy Meal.
6) Make sure the restaurant is planning on having extra staff on hand.
7) Get the terms of the deal in writing so there are no misunderstandings. I have a sheet that I use for this, and I'll post a copy in the file exchange under " Fundraiser Forms & Letters."
8) People get tired of them if you do too many, even if they are different types of restaurants each time. Two to three a year is probably enough.
9) Personal preference here, but I like doing places where you can sit down and see other families from school, versus a pizza place where you're just running in to get carryout (or have it delivered).
10) You will almost always think the restaurant had more sales than they tell you they had for the night. There's no way of knowing if you are right--just smile, say thank you, and take their money. If you're really unhappy, don't do anything with them again; there's another restaurant waiting for your business!