I worked for a building materials manufacturer as a "Benchmarking Engineer" that actually focused more on competitive testing than anything else.
I think the holy grail you are looking for would be the ASTM (
) website. However, depending on your situation, the CSA or UL may be more appropriate.
As far as the day-to-day stuff, I simply acquired all of my company's product line, all of the competior's offsets, and proceeded to analyize all aspects of the products.
One example: The company I worked for made adhesives.
I would prepare a test according to ASTM#xyzwhatever placing a mesh strip imbedded into the adhesive. The adhesive was applyed to various substrates, (i.e. glass, woods, plastics, metals) and when sufficently dry placed into an extensiometer and pulled to gauge adhesion strength.
I would run a sufficent number of samples, write a report, and turn the results over to the marketing guys and the chemists. By being able to compare our product vs. theirs, the chemists were able to add more methylethyl-death and the marketing guys were able to brag about our 35% better adhesion factor.
Some of the "testing" was subjective, but still meaningful if done properly. The results were always appreciated by almost everyone involved, right down to the people on the plant floor.
The applicable testing variables depend on your products, but be sure to talk to both nerdy engineers/technicals and the ponytail wearing marketing and sales guys. Everyone has some special test result they are looking for.