I've been researching dynos for YEARS. I think at this point I'm nearly 9 years of testing and researching.
Before I go into a ton of detail, I thought I'd share some documents and articles with you that have already been written:
Sport Compact Car - August 2004 - What's Wrong with Your Dyno?
Car and Driver - Is your Dyno Lying? - May 2004
I have another one from this month's Hot Rod Magazine doing about the same thing with a Shelby GT500 Super Snake. I'll try to get it scanned in.
I personally have had experience using:
Land and Sea DynoMites
I have done some paper-only research on
Dynamic Test Systems
I'm nearly ready to complete my research and put it all into a nice written document for everyone to read.