You should find a contractor that has experience with refinishing wood floor surfaces. There is a big difference between "repairing" a wood floor and "refinishing" a wood floor. Refinishing requires a contractor to be a lot more skilled than a simple repair job. This is because they will be sanding and refinishing existing wood. If they are not adequately skilled, contractors can sometimes cause damage to wood floors they are refinishing.

Estimates are very important when you are getting your floor refinished. Without an estimate, you have nothing to hold the contractor to if you feel the costs of the project are getting out of hand. If possible, get the contractor to put the estimate in writing for you. While estimates are by definition not set in stone, the actual cost should not be significantly different than the estimate. Having the estimate in writing will give you a reasonable amount of leverage if things go over budget.

Try to find a contractor with references. References are the best way to gain insight on the professionalism and skill of a contractor before you hire him or her.