1: Start by trimming off the ends of each stalk, so that it's neat and fresh. Discard the offcuts.
2: Take a stalk, and with a small knife or vegetable peeler, detach the (reddish) skin at one end and pull away to reveal the green flesh.
3: Pull the skin down to the end of the stalk and discard. Do this all round, so that it is left completely green.
4: A little skin might be left towards the end of the stalk, so be sure to remove this too.
5: You should now have a stalk that is completely peeled. Prepare all the stalks in this way.
6: Next cut the stalks into small pieces.
7: Your rhubarb is now ready for use.
8: You can see details on this video.
Remarks
Rhubarb stems that you buy should be firm, easily snapped and nice and red. If still green, they are not properly ripe; if soft, they are too old. I do not believe, contrary to many other recipes, that it's necessary to blanche rhubarb before using on account of its acidity, and besides, this characteristic acidity is a feature of rhubarb that's well worth conserving.