Doc,
If you're going to do a lot of work yourself on the Security Six, I would get Jerry Kuhnhausens book "Ruger Double Action Revolvers, A Shop Manual". It can be found many places (Brownells, Amazon, etc.)
Remember polish only, I like using a Hard Arkansas stone. Don't change any angles. Take the trigger and hammer out and you will see the mating surfaces. You'll polish the single action sear and can polish the DA primary and secondary pickup surfaces (primary is above the sear, secondary is below). Then smooth the cocking notches on the hammer, again taking care not to change any angles, just polish. You can also polish the hammer dog if you want, that will also help make a smooth DA pull.
There are probably You Tube videos out there, but if you have the Kuhnhausens book, that's all you will ever need.