I hope you don't mind if I seem to gush about the books I've been reading, but one is better than the next. I'm currently reading Writing Alone and with Others by Pat Schneider, and loving it.
"This is a book about being an artist/writer. Whether your purpose is artistic expression, communication with friends and family, the healing of the inner life, or achieving public recognition for your art--the foundation is the same: the claiming of yourself as an artist/writer and the strengthening of your writing voice through practice, study, and helpful (as opposed to damaging) communication with others. Your task, as a writer/artist, is to:
1. Give your art/writing time.
2. Sound more and more like yourself.
3. Experiment, play, take risks, be brave.
4. Believe in the freshness, vitality, and importance of your experience and imagination.
5. Practice in ways that will teach you to recognize your own voice and to increase its range (as a singer learns to sing higher and lower--as a painter increases the number of colors on a palette).
6. Believe in yourself as an artist-in-training, and protect yourself from everyone and everything that undermines that belief.
10. Find and keep in contact with other writer/artists who can provide you with an intimate community of support, give you honest critical response, strengthen you, and encourage your work."