Go to the museum's website to learn what exhibits will be on display during your visit. Museums will usually make resources available so you can educate your children on the topic beforehand. On the way to the museum, ask them to think of two questions for the museum guide—you'll get them excited for the day and foster the learning spirit.
Be hands-on. The museum may be for children, but the day will be more fun for the whole family if parents participate as well, and you'll likely learn a thing or two! You can also extend the learning adventure by asking the museum guides for experiments that are safe to conduct at home. If they don't have any, the museum website can provide suggestions.
Pass on the gift shop. Instead, choose exhibits where you can make your own souvenirs to bring home. Most children's museums have at least one permanent exhibit that involves a create-your-own element, which make for more sentimental—and wallet-friendly—mementos.