Saw some good reviews for this one, including a pretty detailed overview at Cool Tools (which is an interesting site to follow, anyhow.
Learn how to design, make, repair, improve, and maintain sails
If you want to produce sturdy sails for daysailing and cruising, built of low-tech materials you can repair with a few simple tools, The Sailmaker’s Apprentice can show you how. Emphasizing the handwork that distinguishes the highest-quality, most durable sails, sail pro Emiliano Marino tells you how to select a rig, introduces you to sail shape and theory, and then shows you — step by step, with the help of over 700 detailed illustrations — how to sew patches, hand sew rings, fix tears or frayed edges, and stitch seams, not to mention how to make your own sails, canvas sailcovers, and sailbags from scratch.
A visual feast for the sailor as well as an indispensable guide for the mariner comprehensive apprenticeship, this hands-on reference is an illustrated tour of the world’s rig and sail types, contemporary and historical.