Brion Toss Video
The best and easiest to understand resource for tuning is Brion Toss's Video called "Tuning Your Rig." It is available directly from his website (Google it). It will give you all of the readings for your Loos gauge, and show you how to use it properly.The next best resource is Ivan Dedekam's "Illustrated Sail and Rig Tuning." It is published by Dedikam Design, in Oslo (but is written in English), so it may be a little hard to find locally, but it is currently available new or used from Amazon.comAlso check the archives.Fair winds.