Hi Chrysalis,
If time is an issue, the AM/PM yoga tapes by Rodney Yee (Living Arts) take about 15 and 30 minutes. Just doing the 15 minute AM progam helps me be pain-free from my arthritis.
I get low-back pain if I have not been exercising, or exercising without enough stretching. I have found the living arts beginner yoga tape to take care of any lower back pain after a week or two.
However, I have taken yoga classes on and off for many years, so I can just listen and relax. I do recommend trying a class to get started.
I think much of the benefit for me is from the relaxation/meditation.
Good luck!
Joan
ps here is a link to some desk yoga for the days when you have to work 15 hours:
Desktop Yoga - prevention and healing of RSI and Carpal tunnel syndrome - help your hurting hands