If at all possible, book your cruise early. Order the free DVD from the official website, and while you're there, look at the overviews of the different staterooms. You may want to book your trip through a travel agent. They can often find discounts and will be able to answer all your questions.
When packing, make sure you bring your bathing suit, sunscreen, all medications, your camera, and your passport. Dress in layers and make sure you have a light jacket with you no matter what time of year you travel. Also bring a sturdy pair of walking shoes for shore excursions.
Don't overdo it when you eat. One of the major complaints after a cruise is about weight gain. There are three main dining rooms that your party will rotate between; Lumiere's, Parrot Cay and Animator's Palate. There are also several buffets and quick service options onboard. Palo is an adults-only restaurant where passengers 18 and over can dine in a relaxed atmosphere for an additional charge.
The Disney Magic offers plenty of opportunities for the kids to have the time of their lives. "Youth Clubs" are broken up into age groups and feature special activities and a chance to hang out with other kids their age. There are also first-run and classic Disney movies for the whole family to enjoy, plus live shows based on Disney characters or movies. Goofy's Pool is for the whole family, and Mickey's Pool is designed especially for the little ones and includes a splash zone.
The adults on a Disney Magic cruise will be surprised at the number of activities available only for them. While the kids are playing at the youth clubs, enjoy some time in the Vista Spa and Salon. There's also a state-of-the-art fitness center that's adults only and it includes classes as well as personal instruction for an extra fee. Adults can relax at Quiet Cove Pool. There are nightclubs and lounges too for adults. At the end of the day bring the entire family back together for dinner and a show.