from the room. tape up any cabinets or cupboards, as the dust you will create will get everywhere.
walk over the floor with your nail set and hammer. drive down any nails that are sticking up from the floor. be sure you don't miss any, as these will quickly tear up your sanding block. vacuum the wood floor thoroughly when you are done.
put on your knee pads and mask, then walk to one corner of the room. place a piece of 60-grit sandpaper around your sanding block and get on your knees.
sand the floor, starting with the board in the corner of the room. apply light pressure to the sanding block 