Jana Tidwell of AAA suggests empowering your kids by getting them involved in the planning of the trip. Aside from packing their own mini suitcases with some of their favorite outfits, tell the kids to pick a favorite "friend" to bring along (usually a stuffed animal), and suggest ideas for car games that they can find and pack.
Tidwell also says a small cooler with healthy drinks and snacks is a great idea not only for nutritional reasons, but also because food you buy from the local grocery store is bound to be a lot cheaper than anything you get along the highway. Cheese sticks, crackers, grapes, strawberries, popcorn bags and pretzels are all good choices, along with juice boxes and water.
If you want to include a little candy, that's fine, but don't go overboard. Your kids are going to be in a confined space for long stretches of time, and anything that gets them bouncing off the walls is generally not a great idea.
You may find that you need extra breaks with kids in the car, and Tidwell says it's especially important to make use of those highway rest stops and pullovers. This recharges everyone's batteries, and increases the chance that the following miles will include fewer distractions for the driver.
A great idea is to plan stops at small attractions along the way. A road atlas will often have many of these listed, as will travel guide books. You can consider doing internet searches for mini-golf courses or state parks. My sons and I take baseball trips and often plan on stopping and seeing a movie in the middle of a long drive.
Anyone interested in more information on AAA can click here. An annual membership varies in price depending on the level of membership required. Membership includes emergency road service, discounts at motels, hotels and attractions, as well as trip books, maps, and travel planning assistance. Tidwell notes that AAA is a non-profit organization.