A wood basement subfloor typically is easier to prepare for flooring. The goals are the same: seal and level it. Sealing is done with a moisture barrier such as plastic sheeting or builder's felt depending on whether moisture is a problem. The subfloor can be leveled by installing a thin plywood over the top of the floor.
If the wood floor squeaks, install ring-shank nails through the subfloor and into flooring joists. You can identify the location of the joists by looking for rows of nail heads.
If your wood floor requires additional insulation, refer to Basement Walls for information on various insulating materials and how to install them.