What I've done in the past is: 1) rip up the carpets and tack strips 2) make sure any and all staples or nails are pulled. 3) fill any holes with wood putty 4) rent a sanding machine, buy some sanding belts, and work over the floor, going WITH the grain. 5) hand sand in the corners 6) vacuum twice and damp mop to get rid of all dust 7) finish with at least three coats of polyurethane varnish. This made the old hardwood floors look FANTASTIC again. If you like, you can skip step three and make your own wood putty out of the sanding dust from step 4 and some white glue and patch the holes after step 6; this will match the wood of the floor perfectly since it IS the wood of the floor. You'll have to hand-sand the patches, though.
Your asking how to do it and looking for a job doing it simultaneously? Good luck. Check with your local flooring companies.