How long are non compete clauses valid?

I was fired in September 2010 after three months of working in staffing assistant/sales role at an agency here in Columbus. For the first two months I assisted with filling job orders and contacting temporary employess. After 2 months I moved into a sales role and still assisted in helping fill job orders and sourcing candidates.

I would like to open a telephone names sourcing service. In this role I would be helping agencies find passive candidates to interview.

I signed a non compete agreement. The owner never gave me a copy of it. They are also fighting me on every level of my unemployment claims. We do have a hearing scheduled. ODJFS has found in my favor becuase they have not produced any documentation that supports their claim for terminating my employment.

What is a reasonable time frame for a non compete clause to be valid? I did not recieve any training from them. It has been nearly 5 months since my termination.