This is a great book from Weems Westfeldt at http://www.edgechange.com , on skiing, focused more on how to approach skiing and learning but with very good technique tips as well. Well worth reading for any ski enthusiast.
The central idea is the Sports Diamond, four tools that you should be aware of and that you can use and rotate through them to break through the performance plateaus:
Some of the skiing principles proposed are:
There's more talk about managing fear and excitement etc.
Among the technique tips, there are a few things I don’t agree, like advocating a wide stance (while none of the photos in the book support it) and inclination versus angulation.
Overall though, it is very good and it makes a lot of sense, as it insists on general aspects of ski technique, like transition, outside ski etc. There are some very advanced and not widely talked about tips as well, so overall it's a great technique guide as well, much better than many I've seen.
Here are some notable ideas that he elaborates on:
There are more tips for skiing the steeps and powder etc.
For 5$ it probably is some of the best bang for the buck among ski books.