Here is an article from our sister site Babyfit.com with some tips that might help. How to Raise Natural Eaters--and End Dinner-Table Fights Forever: The No-Nonsense Way to Teach Kids to Eat Right
As noted at the bottom of this article, Ellyn Satter is a great resource for feeding children and one many dietitians use for their own homes.
Research has shown that it can take 10 tries to get kids to eat a new food, so don't get discouraged. The meals in this article are kids' menu favorites with a nutritious twist that should make the cut for both parents and kids and might be worth a try. 9 Favorite Meals Made Healthier to Please Moms and Kids
Hope that helps.