In the last year or so, the upgraded SkiRacing.com has added a great section: Backshop. http://www.skiracing.com/premium/backshop-5-simple-steps-for-fast-skis/ This series has been consistently great and I can't recommend their tuning series highly enough. Jim Schaffner is a Master Tuner and a very good teacher.
As a contrast, although there are TONS of tuning videos on youtube, but they are extremely inconsistent in the quality of information. In the case of You Tube, BUYER BEWARE!
So if you are dying for more information to make your skis work well, Check out The Backshop.
See you on the hill!