Although most of us view yoga as simply a physical discipline, there is a far more spiritual dimension to it. The entire philosophy of yoga has been contained in Patanjali's Yoga Sutras. Sutra is Sanskrit for "thread" - the sutras are a collection of terse aphorisms threaded together, laying out the whole of yoga.
Translations of these sutras have been done by males over the years and although there are some wonderful books on the subject (Iyengar's "Light On the Yoga Sutras" for one), I have found these books to be rather dry. Well known yoga instructor, Nischala Joy Devi has written an entirely new and feminine perspective on these ancient proverbs. Devi writes in an almost poetic manner and substitutes words that are 'negative' with a more heart centered counterpart. For example, for Aparigraha which is often translated as non-greed, Devi uses "awareness of abundance". This is a very nurturing viewpoint that makes the sutras "friendlier" and more easier to relate to. Meditations and practices are sprinkled throughout to help intergrate the vibe of the sutras into your heart.
She covers books one and two of the sutras and did a brief scan of book three. I am somewhat hopeful that she is intending on covering books three and four (she didn't mention book four at all) in a further volume, but until then, this is enough food for thought for now.