BrianG, you asked how to get ground speed from looking at the DME readout.

If you start your stop watch and look at the DME see how many miles click by in one minute. If you see 10 miles go by in one minute you're doing 600 KTS.  All you need to do is take the miles that click by in one minute and X by 60.

For example you see 7.5 miles go by in one minute: 7.5 X 60=450 KTS.

Poor man's G/S readout.  ;D

As for Mark's descent profile... While above FL290 use Mach instead of IAS.

You are at FL 370 at Mach .80. When ready for descent, start the nose down while slowly closing the throttles. Keep Mach .80 until you get into fatter air. Around FL 300 to FL 290 transition to IAS and continue descent at 290 KTS. You can change the speed to adjust the descent unless ATC has given you a speed. All the while you need to keep updating your descent profile to see how its going. If your numbers show you a bit low on the profile, add a little power and re-check the profile. If ATC assigns you a speed, as they often do - for instance a lot of times they will say "you are leading the pack, keep your best forward speed."  No problem, just add power and get the speed to the barber pole if you want, but keep an eye on the profile since you will have to make some adjustments in the IVSI to stay on the profile.

Remember, flying is mostly art and maybe a touch of science.

Lou