A lot of people like Rachael Ray books because she makes things simple - not a lot of measuring, just "eyeball" a lot of things. Jessica Seinfeld has a book with healthy alternatives for kids. I also agree that the library is a great resource so you can try some recipes before buying the cookbook.
I would caution you about going to company websites such as the Kraft site suggested by another poster. Those sites will tend to feature their own products, which have a lot of additives and preservatives in them. And of course, they are often more expensive. You can read labels too - try not to buy anything that has high fructose corn syrup, "enriched" flour (it's been stripped of nutrients and then had just a little bit added back in), partially hydrogenated fats/oils, or a lot of salt and sugar.
Also, buy local farm produce as much as you can - there is much more nutrition in something grown locally than something that was picked 2 weeks ago before it was ripe and then shipped across half the country. You can shop at farms themselves or seek out a farmer's market.
And "what do I serve with that?" - fruit or vegetables. Go for a colorful diet - things with all the different colors, not just green, but also red, purple, yellow, orange. We steam a lot of vegetables and just serve them plain or with a tiny amount of butter or healthy butter substitute. Salad bars are fun at the table too - kids like to serve themselves and they make better decisions when the stuff is in front of them. They also like to dip - so raw veggies dipped in hummus is a great choice. Grilling is fun too - make kabobs out of peppers, onions, small potatoes, etc. I just coat the vegies and the chicken or fish with canola/olive oil and fresh herbs, whatever I have on hand (thyme, parsley, rosemary....). Try fresh-picked corn on the cob, put in foil with a little butter, water and salt/pepper, and grilled.