We keep lots of great books in the studio library at Saori C. Jewelry Designs but we refer back to the books of metalsmith Oppi Untracht far more than those of any other author. Oppi was (he passed away in 2008) a New York master metalsmith, who wrote what is probably the best all-around jewelry making and metalsmithing guide ever. That book, Jewelry Concepts and Technology (which will run you close to a C-note, but is worth every penny), is the go-to reference and all-around bible for jewelry designers, craftsmen, and manufacturers the world over. It's chock full of the four t's (tools, tips, tricks, and techniques) and no serious jeweler or jewelry designer should be without it. We refer to it at least weekly, and it's certainly the most dog-eared book in our studio.
Oppi also wrote several other great books about specific metalsmithing techniques (Metal Techniques for Craftsmen, Enameling On Metal), and his magnum opus, an amazing book on the techniques, designs, and history of Indian jewelry and jewelry making, Traditional Jewelry of India, which is out in paperback and well worth acquiring.
So if you're looking for some great additions to your jewelry library, or are just getting started and trying to decide in what references to invest your hard-earned money, give the works of Oppi Untracht a look. He won't steer you wrong.