You need to dig up the roots (terribly important part as you wouldn't want to do all this underground) and shave the outside to just have the white/slightly off white innards. This may be difficult as they do get quite gnarly. Slice in about ¼ to 1/3 inch thick slices and place in a single layer in a food dehydrator or in a warmed oven over night. When the chips are snappy (easily snaps with no bending) place the chips in a food processor (no blender as it will be very difficult to mix and get an even powder).

Store in a dry, clean glass container or a zip locked plastic bag. It is best to use the flour before the next season. It seems to take on a very dusty flavor if kept much longer than a year.

I've never tried to make bread with more than a ½ cup to 2 cups regular wheat flour. I use it something like potato flour (which, consequently you can make the same way as the artichoke flour). It's VERY heavy if you use much; your bread turns out like a brick.