Can somebody help me with information on finding my kids and child custody? It is urgent.

You really need to give a lot of more details

I will assume that someone, most likely the other parent has the children with them right now and you do not know where they are at??

Normally it is easier to trace the other parent though drivers licence, social security numbers, relitives and the such.

If the kids are of school are, following their school records shouold be possible.

On child custody, you will need an attorney and file for a hearing before a judge. If the other partner already has legal custody you will have to file a motion in the court that awarded the custody to have the custody changed. ( or at least to get visitation rights)

If the children are not with a parent and you have legal custody, then it may be a police matter.

The first stop will be a good attorney who has experience in these matter and most likely a good search company or private investigator

This is not a matter than any of us on these boards need to try to address but you need professional help