Books:

The Natural Knitter
by Barbara Albright

Wonderfully informative about natural fibers, although focus isn't on sustainability per se. Its a pleasure to read, with beautiful photography and layout.

No Sheep For You
by Amy Singer

Focuses on non-wool yarns, such as bamboo, cotton, silk, and linen. Not so much on sustainability, but it's incredibly useful for learning about what kind of knitting is best suited to these fibers.

The Knitter's Book of Yarn
by Clara Parkes

Excellent resource about the qualities of different fibers and yarns. Does have a couple of pages that talk about organic and minimally processed farm yarns.

Natural Knits for Babies and Moms
by Louisa Harding

This book features organic yarns in its patterns. It doesn't offer much introspection or information about choosing green yarns, but the patterns are darling and are designed for some well known organic yarns

Nature Babies
by Tara Jon Manning

Cute knitting, sewing, and felting patterns with an emphasis on recycled and natural fibers. Discusses the ethics of green crafting a bit more directly than most books.

 

Further web reading:

- Lotus Organics Blog (very well researched posts on bamboo, wool, silk, cotton, and more)
- Ravelry GreenCraft group (note: must be a Ravelry member to read it)
- Ask Umbra's excellent advice on natural vs. polyester clothing.

 

Stores with a special emphasis on green yarns:

- Earth Friendly Yarns
- Near Sea Naturals
- Granola Yarn
- Chamomile Connection
- Ecoyarns (Australia)