My son used to be a great eater, even veggies, until he turned one year old. He is now almost 2. It is important to know that toddlers will eat when they are hungry. All though it is very important that they get their veggie intake, don't force food on them. I am a lot like you. I am not a very good eater, especially when it comes to my vegtables. We never forced our daughter to eat anything that she did not want to. Using that concepts does help improve their eating habbits. Simply make the healthy food available for them. My daughter will be 14 in a few months and has great healthy eating habbits. As of now, my son goes back and forth with his eating habbits. I do offer him veggies on his dinner plate. Sometimes he will eat them, sometimes he won't. Don't get frustrated though. The more you offer it without forcing it, the more likely it will be that your kids will give it a try. Also, my pediatrician told me to give him 1/2 of a vitamin, such as Flinstones. He doesn't like the taste, so I cut it up really fine and mix it in his cream of wheat or other warm food.
It is not recommended to give children under the age of 3 celery, peanut butter or raisins. The celery is too stringy, the raisins can get lodged in their throat and the peanut butter can cause an allergic reaction. Check with your pediatrician before offering these type of foods. If you offer you kids grapes, make sure that you cut them into small pieces to prevent choking.
Finally, I found a recipe in a parenting book that I check out from the library. It said to stir, dry finely chopped spinach and one jar of baby food butternut squash into brownie mix. I have not tried this yet though. It is just a sneaky way of getting them to eat something healthy. Give it a try and see how they like it.