Here are some sources of information Iíve found useful.
Sharpening and Testing Plane Irons by Brent Beach: This excellent comparison of a variety of plane blades is what motivated me to get a microscope and start tests of my own. Although the method he uses to evaluate blade wear is different from mine, our results are similar.
Crucible Steel Services This is the manufacturer of the CPM 3V alloy Iím using to make my blades. Click of the Data Sheets tab to find information about the properties of their steel products.
Selecting High-Performance Tool Steels for Metalforming Tools This article from Metalforming magazine was written by the Director of Technology at Crucible Steel. Although it is primarily concerned with choosing steels for work with metal, its description of the properties of steel alloys is valid for other applications such as working wood.
Kato, Chutaro: Effect of Knife Chipbreakers on Surface Finish An excellent study of chip formation that was done using a super-surfacer, which duplicates the cutting action of a hand plane. [In case this link doesnít work, an edited version of the study is available here.]
Heat Treatment, Selection and Application of Tool Steels by Bill Bryson, Hanser Gardner Publications, 1997. This book contains detailed information on how different alloys should be heat treated and what their resulting properties will be.
Modern Steels and Their Properties, published by Bethlehem Steel. My copy is the sixth edition, published in 1964, so it doesnít contain information about modern alloys. It does have detailed information about carbon steels, and discusses properties such as grain size.
The Leitz Lexicon: Handbook for Woodworking Machine Tools, Edition 1, Leitz GmbH, 1997. This is a technical handbook that describes the Leitz product line of saw blades, shaper cutters and other cutting tools. It has a section on cutting tool principles and some electron microscope images of worn edges that I would have used on this site if they had not been copyrighted.
Understanding Wood by R. Bruce Hoadley, Taunton Press, 1980. The chapter on Machining Wood has good illustrations of chip formation at various cutting angles, and the illustration of a worn edge was helpful to me in interpreting the bright lines that appear on blade edges as they are used.
The Complete Guide to Sharpening by Leonard Lee, Taunton Press, 1995. The comprehensive theoretical and practical information about tools and sharpness in this book make it indispensable. Its electron microscope images of blades honed on different abrasives give a much more detailed look at how steel responds to sharpening than I can achieve with my small microscope.
Wear and Blunting of the Tool Corner in Cutting a Wood-Based Material by W. M. McKenzie and H. Karpovich, Wood Science and Technology, vol. 9 (1975) pp. 59-73.
Sharp and Sharper by Aimé Ontario Fraser, Fine Woodworking No.157 (August 2002). A good description of using nine honing abrasives, with electron microscope images of the edges produced.
Different Strokes: A Plane Blade Trial by Richard Vaughan, Australian Wood Review, Issue 33 (December 2001). An edge retention test similar to Brent Beachís, but the blades were used to plane 500 lineal feet of Sydney blue gum, then 300 lineal feet of brushbox (ďan infamous blade blunterĒ), then 40 lineal feet of West Australian sheoak. The winners were the Academy Saws M2 blade and the Holtey A2.