Travel to the city of Gilroy. The nearest major airport is the San Jose International airport (SJC).
Buy tickets at the gate or in advance online. The website offers special deals, discounts and information on events, pricing, hours and more, so it is a good idea to check it out before you go.
Plan ahead. You don't have to scour the online park map to find the best route from ride to ride, but you can if you want. Also, pack sunscreen, hats, sunglasses and appropriate clothing for the time of year. You can buy these things inside the park, but they get a lot more expensive inside.
Apply your sunscreen before you leave the hotel, even in winter.
Plan to take your kids back to the hotel for a couple of hours after lunch. You can get your hand stamped and come back when they are rested.