Working Obsidian:
Adventures in the Scenic Northwest, with D.C. Waldorf. Segments include a stop at Glass Buttes to collect obsidian, then it's off to the Cascade Range to knap a nice point. Includes a section on using sawed slabs,  breaking up a monster boulder, and how to use those small chips and irregular chunks. It has lots of good instruction on the nuances of edge preparation and flake removal. Now digitally re-mastered with additional scenic footage, this is one of the most visually stunning knapping videos ever made.  Though intended more for the intermediate knapper, beginners will also find it very useful. Running time 1 hour 55 minutes.  New low price $20.