Congratulations on wanting to adopt a vegetarian lifestyle.
I would get a few cookbooks to help out. Two of my favorites are:
Lean and Luscious and Meatless by Bobbie Hinman and Millie Snyder (great stew recipes any kid would love)
The American Vegetarian Cookbook from the Fit For Life Kitchen by Marilyn Diamond. (The book that helped me go vegan in the first place)
Of course there are other great veggie cookbooks, but those are two great ones.
As for the fussy eating... how are you serving the green veggies and legumes? The trick when trying to get kids to try something new, in my humble opinion, is to start out by making them extremely palatable and working towards healthier versions later.
For example, broccoli with a nice vegan ranch dipping sauce. Or zucchini sticks breaded and baked and dipped in ranch dressing.
For legumes, try stews or hummus.
You'll also get some tips for transitioning your children in my book Raising Vegan Children in a Non-Vegan World
. I have a whole chapter on transitions.
Good luck to you!