I have primary custody of my children, their father has seen them only one weekend in the past two months. Can I move out of state, or am I bound to stay in the state I am in?

This would depend on what you have set up in your visitation paperwork. You are required to give notice to the biological father that you are moving, no matter if he is "active" in your children's life. If he wants to fight it then he must do so accordingly, I would recommend talking to him. Send him a certified letter with return receipt stating that you are moving to so and so state with all of the information including new address phone numbers whatever it may be. But some people set up in there visitation paperwork that if a parent is to move out of the state it has to be approved by the other (within reason).