With kids, expecially, you are crazy to not have a will. If one of you dies, your state law for intestates may well give part of your assets to the kids, with someone as trustee. If you both die the kids probably get the estate and the court will pick a trustee for them who will then manage their (formerly your) money. That will probably cost at least two hundred basis points plus mutual fund management fees. The kids will probably get 100% of the money at the ripe and mature age of 18. Do you want any of that? If not, you probably need a trust to manage for the kids. It's not uncommon for a trust to distribute assets based on age, part at 25, 35, and 45 for example. In the mean time the trustee can be empowered however you like; support them completely, pay only for educational expenses, pay for some expenses, etc. And you can name the trustee, someone you trust. (Note that the trustee job is different than the executor job.)
As mentioned, getting a stranger (like a bank) to manage the trust depends on its size. Small trusts, if accepted at all, might be managed by a bank service (aka near-clerical) group that functions almost like a discount broker but charges 2-3%. They will invest in whatever they feel like, including metallic gold, unless the trust includes an investment policy. You probably don't want this. Even if you do, you probably want to set this up ahead of time.
Also, you have personal property. Contents of the house, cars, etc. Who gets that and how will it be divided?
Circling back, what if you die and your wife gets everything smoothly? Is she equipped to do the necessary estate planning for herself? If no, that's another reason to get it done ahead of time. If she is not financially savvy at all, you may want to arrange a trust for her benefit. That has the added benefit of protecting your money from, say, her next husband or from scammers.
The list goes on, and on, and on .... Legal help is necessary.
