Hi everyone,
In regards to what Sean said about leaving a blunt square edge in order to not loose the carbon content, I just remember a trick that was given to me by Tom Sterling (who had it from an old jeweller...etc etc

)
In order to reduce the sharpening time once you got your tool harden you can do as follow:
Take a small jar and fill it halfway with boric acid, then fill the rest of the way with "rubbing" alcohol. (in USA that is 70% isopropyl alcohol from the . store), but the type of alcohol isn't important. Ethanol is fine, and probably methanol (wood alcohol) would be OK too.
This simply provides a supersaturated solution of boric acid and the alcohol readily burns away, leaving the boric acid behind. Boric acid will melt in the forge, and is a common ingredient in lots of kinds of soldering fluxes. It's purpose is simply to exclude oxygen from the hot metal. Oxygen will combine with the carbon in the steel forming CO and CO2, reducing the carbon content of the surface layer (decarburization).
And as to how many times you should dip the blade well, dip then burn enough times that you get a good, solid white coating of the boric acid on the blade. Better to have more boric acid on the blade than you need than to have too little...
I used the previous methods for doing a crook knife and it has worked well for me, actually it has worked so well that a friend of mine went away with the knife and I still have to do another one....
Hope this helps.
Christophe