I have found that my kids' tastes change frequently.  They seem impossible to please.  Just when I find a recipe they like, the next time I make it, they scowl. 

We often go through these cookbooks together to not only cook as a family but to let them select their meals.  They enjoy them even more when they get to help in the kitchen!  I'm sure there are a gabillion kids' cookbooks,  but here are a few we like.

The Eat Clean Diet for Family & Kids by Tosca Reno

Brain Foods for Kids  by Nicola Graimes

Super Foods for Babies and Children  by Annabel Karmel

the petit appetite cookbook (Easy, Organic Recipes to Nurture Your Baby & Toddler) by Lisa Barnes