The Art of Shetland Lace

This book is not the be-all and end-all of lace knitting, but it is a great reference for shetland lace. There are photos of some old elaborate shetland garments (including lacy socks), a brief history, 36 traditional lace stitch patterns (though some are more involved that it seems like more than 36), and then patterns for 7 lace garments. Given the age of the original book, the photos are slightly murky by today's standards. 

Northern Knits: Designs Inspired by the Knitting Traditions of Scandinavia, Iceland, and the Shetland Isles

Inspired by folk traditions and the wholesome purity of natural wool yarns, this collection of 20 stunning patterns for both traditional and contemporary women’s garments and accessories is perfect for the modern knitter. The traditions of the quintessential knitting cultures of Iceland, Shetland, Norway, and Sweden are examined, from descriptions of the wools and yarns to the history of the clothing traditionally made from them, including breathtaking photomontages of these classic vintage styles.