I was about 9 when my mother converted and started teaching me. I feel that my father's opposition created an atmosphere of religious conflict and aided my decision to get baptised. I would recommend that you not feed into the JW notion of "oppressed." Create an atmosphere of humor, acceptance, and toleration. Make sure your children make plenty of friends outside of the religion. That was another one that got me. My mother made sure I always had plenty of JW associates. Since my father was busy at work, he didn't have the time to do the same. We lived in a rural area, so that controlled my peer group.
If your children are raised in an atmosphere of open toleration and opportunity they will not chose to limit themselves. If you create an atmosphere of opposition then that brings the cultic pressure of fear/desire into their lives. Be mindful of your wife's possible effort to instill judgemental attitudes (you must LIVE that the world is a great place), fear (the future IS bright in your family) and desire for love (your acceptance must be complete, and never hinged on what they do. This is the only way to be superior to the distorted conditional cult love).
Be active. Please I beg you. I'm 23, and I still have time to start a new life. I regret how my youth was spent. Keep in mind, your children are NOT capable of the level of though it requires to refute JW teachings. The simplistic doctrinal issues and dizzying prophetic claims are highly persuasive. Your children can not be put into a choose A or choose B dilemma from a doctrinal issue. I believe it would be unfair to even put minors in such a situation.