It's nice to know a hundred knots, but those who do usually find that just a dozen or so meet their needs. Here's a practical collection of the essential knots for simple boat work, with a few others thrown in just because they are beautiful and useful.
Illustrated with clear and simple diagrams, it has easy-to-follow text. It includes a drop-down chart to match needs to specific knots as well as a guide to fiber characteristics to help you select the right rope for the job. This slim volume can be carried in a pocket until the sailor-in-training knows them all by heart.
Saddle-stitched, laminated softcover, 4 1/4" × 6 1/2", 43 pages, 2006. The book is available on its own or with two 60" lengths of rope and a 2" diameter ring for practising. The rope and ring set is also available separately.