Do take a break
Without children, I think I could have went on every ride at Disneyland in a day. With children, that's just not possible. Those smaller legs can only take so many steps, and every one of my steps is about three for my kids. Breaks are a necessity if you are going to have a magical trip to Disneyland. There were times that we would just sit down in the shade with a slushy or a pretzel for a half hour, which allowed our family to recharge and get back to the attractions.
Do listen to your kids
I had so many plans for my children before getting to Disneyland, but what I learned from my first few hours in the park was to listen to what they wanted to do and put those attractions and experiences into my itinerary. I noticed how much more fun our family had during our second day at the park once I knew what my children would enjoy the most. My boys wanted to ride Astro Orbitor, which to me wasn't really on my radar. We decided to ride it, and what do you know... it was one of their favorite rides!