Recentally my husband left state with my 2 children without my consent or knowledge. Now I do not trust him not to take my children away from me again. How do I file for full custody of my children? Will this prevent him from doing this again? And will I be able to leave state with my children once I do file for custody of my kids?

Please pay more attention to posting guidelines. There is a Read First sticky in most forums that directs questions of a legal nature to this forum.

The issue is not custody, but visitation. The children are not just yours, they belong to both of you. You are leaving out some pertinent details here. Did your "husband" MOVE out of state or just take a trip? Are you divorced or were you in the process of one when he left? Was there ANY court orders governing custody or visitation at the time?

Unless your husband violated some court order then its unlikely you will get sole legal and physical custody. You should get primary, but he will probably get visitation. It may be supervised visitation, however.

As to how you file, you go to your local Family court and submit a petition for custody. I would highly recommend getting an attorney to do this for you.