We were married in 1999, and had two kids by mid 2000. Shortly after our second kid, my wife decided that two kids were too much so she moved out. I tried to keep things together for the next couple years, but it never worked. In 2004 she moved out for the last time, and had little contact with our kids for a while. Sometime towards the end 2005 she moved out of state , I think she is some wheres in New Mexico. The kids and I have not heard from here in almost three years and we want to rid her of our lives. I am a 35 year old unemployed student and cannot afford a lawyer, any one have any ideas on how I can file (myself) for a legal separation and for custody of our kids, without having to serve papers to her. I have talked to her parents and they don't even know how to get a hold of her.

Basically you can't do this yourself. If you don't know where she is you need to hire a licensed private investigator to find her. You can sue for divorce by publication but you need Court approval to do so.

Yes, she has to be served one way or the other.