If you are looking for a guide to herbs for healing and the properties of herbs in general look no further than Encyclopaedia of Magical Herbs (Llewellyn's Sourcebook Series). The Book is one of the Cunningham book series and clearly laid out and easy to use, with many different herbs and flowers covered. Many common ones and a few herbs I'd never heard of and even objects I'd never have thought of as magical items, like carrots and potatoes are mentioned. It Gives you the name of the herb with a line drawing of it it's folk names gender planet element and powers, as well as it's magical uses great for wiccans and Pagans.
I'd recommend the book to anyone with an interest in herbs whether it be magical or not as it gives some fascinating information about the plants and their folk history. If your interest in them is magical then it's also very good as a reference book and has chapter on the powers of herbs and how to perform magic with them which is easy to understand, it explains how to charge herbs before using them in spells amongst other things.
I use this herb book quite regularly in my work and think it would give a valuable contribution to any pagan library.