The BEST one, I think, is The Herbal Tea Garden - Planning, Planting,Harvesting and Brewing - a Garden Way book by Marietta Marshall Marcin -growing, medicinal uses, details on brewing, parts used, taste, quantities,and lots of different blends to try

The Herb Tea Book by Dorothy Hall - good basic information on growing andusing the herbs.

Tea and Tranquility by Adelma Grenier Simmons ( the late owner of Caprilands Herb Farm) - folksy; recipes she served at Caprilands

Encyclopedia of Juices, Teas and Tonics by John Heinerman

Healing Teas by Marie Nadine Antol - how to prepare and use tea to maximizeyour health.

Herbal Teas by Richard Craze - more than 60 soothing recipes

Taking Tea by Andrea Israel with recipes by Pamela Mitchell - The Essential Guide to brewing, serving, and entertaining with Teas from around the world

Perfect Cup of Tea by Arthur Gray, edited by Pat Ross

The Charms of Tea by Victoria Magazine - Reminiscences and Recipes

Herbal Tea Gardens by Marietta Marshall Marcin - 22 garden plans for your enjoyment and well being

The Harrowsmith Illustrated Book of Herbs by Patrick Lima - great chapter onherbal teas.