Resurface (or cover) damaged wood door?
If you'd rather not replace it and have some time to kill it is possible to re-surface the door.
Door skins are thin veneer sheets meant for this purpose. The difficult part is ensuring the old doors exterior is flat and secure to the frame.
Remove the knob and window frame. Patch and sand the old surface. Glue and nail and bowed/loose sections. Apply contact cement to old door and press new skin in place.
Paint or stain as normal.