A revolver trigger job and action smoothing consists of using fine flat stones to smooth trigger/hammer sear surfaces to remove tool marks, deburr mating surfaces, and generally smooth action parts to reduce rubbing friction. It may involve lightening or replacing trigger, hand, and hammer springs, solvent cleaning, lubrication, and reassembly. The emphasis is on smoothing action parts, not removing metal to the point that timing is affected.
The Ruger single action is particularly easy to work on, and well within the abilities of a home tinkerer/pistolsmith. The action parts are heat treated all the way through, unlike Smith and Wesson and earlier Colt double action guns. Colt single actions (and most of the clones) use casehardened action parts, and it's relatively easy to work through the case, making the gun unsafe to fire.
For action smoothing tips and procedures, try checking out some of the cowboy action shooting sites, particularly those by Paco Kelly.
HTH
John