Hi Hilton,
The easiest way of removing fluff and hair is with small tweezers. For a good cheap source of tweezers try the make up section at the supermarket.
Use dry kitchen paper or cotton buds with a small touch of white spirit (be careful it doesn't attack certain plastics and paint finishes), for removing crud. With excessive crud on the wheels, try using a wooden matchstick or a coffee stirrer, to flick it loose. DO NOT use the blade of a screwdriver as it will scratch the wheel tread and cause more problems later on.
Usually the only things that really need oiling are bearings and pins on metal coupling rods. Apply a small drop of oil with a fine point needle. Too much oil will attract dirt so if you have applied too much oil dab it with kitchen roll to soak it up and remove the excess. Unless you are absolutely certain it needs oiling it probably doesn't.
Check any wires for loose connections, pulls, nicks, etc. Resolder any loose connections and protect any nicks in the wire sleeving with a short length of heat shrink. You may need to replace the odd wire if it has been really badly damaged but you can usually get away with rejoining and covering with heat shrinking.
Check any wiper pickups are making good contact that they are not binding on the wheels or floating free.
Try and run you loco on a rolling road, check for any binding and if running is erratic then check for poor electrical contact.
Most of the time, removing the fluff, cleaning the wheels and checking the pickups will be all a loco needs.
Take you time, don't rush the job and don't over oil it.
HTH
Peter