I take 95% of my output over a hard 20minute interval. Once or twice a year I'll try doing a 1hr time trial, but on a trainer you may have a tough time going full on 100% for an hour like that. This is what is described in the "Racing and Training with a power meter" book.

There is also a ramp test, but I've never tried it. http://www.flammerouge.je/content/3_...functhresh.htm

PS I used my KK road machine for training with power last winter using my custom PC software in my sig (for realtime power output info and graphs). It also spits out .fit files which I import into WKO+ for better analysis. I've since purchased a powermeter and found the KK road machine equation to be pretty darn close to the same readings.