Often we focus on the technical aspects of learning to draw: rendering, shading, perspective, proportion, etc. but if you're hoping to make art that addresses the Faery realm there is also a whole other world to take into consideration beyond the simply technical aspects. This is not to deride technique and matters of craftsmanship as those are the important vocabulary in the language of artistic expression. Someone once wisely asked if you cannot draw what you see with your physical eyes, how can you draw what you see through you inner vision? :) I think that someone can learn to skillfully render the human figure and wings and be able to incorporate them together, but that in itself will not a faery artist make.

The following are some books which I feel would be really helpful to a beginning (or  seasoned) artist which will take you beyond the technical aspects of art.

Art & Fear: Observations on the Perils (and Rewards) of Artmaking by David Bayles and Ted Orlando
This book is not specifically related to Faery art, but it has a lot to say about the process of making art in general and about the challenges that can often prevent us from making art that is important to us. It is full of really great insights, but isn't a dry read by any means.

Drawing Closer to Nature: Making Art in Dialogue with the Natural World by Peter London
Faeries are intimately tied with the sensual, natural world all around us. This book is a really interesting look at how art can serve as a form of communication between humanity and nature.

The Inner Reaches of Outer Space: Metaphor as Myth and as Relgion by Joseph Campbell
Written by one of the most prominant mythologists of our time, this book contains an espcially relevant essay on the role of the artist as a mystic and shaman.

The Mission of Art by Alex Grey
This book aims to bring art away from its purely intellectual aspects and back towards a spiritual practice.