If I have everything in a trust, do I need to put the children's names on the house title so to avoid probate?

If your house is in your trust then do not need to do anything else to avoid probate. You should double check that a deed has been recorded passing the title to the trustee. This is a step that many people overlook.

This is true of other assets. They are not in your trust unless you change the title to the assets.

I agree with the first answer. It is absolutely critical to confirm that the trustee of your trust is currently the titled owner of the real estate. If you deed the property to one or more of your children rather than to the trust, the terms of your trust will not reach the property because it does not own it. Also, you should make sure that the trust is listed as an additional named insured on any homeowners or property insurance that you have for that property.