Here is a selection of excellent non-fiction books I'd recommend:

Writing

On Writing                                                 Stephen King (Down to earth - no glamour, just do it)

Becoming a Writer                                       Dorothea Brande (The original classic)

Getting Published                                        Harry Bingham (Behind the scenes, useful)

Writers' and Artists' Yearbook                        A&C Black (Must-have, if you want to get an Agent/Publisher)

Dynamic Characters                                    Nancy Kress

Creativity

The Artist’s Way                                         Julia Cameron (The Queen of Creativity)

Life Choices, Life Changes                            Dina Gloubermann (Fabulous book about using image-work to

                                                                shape your life)

Creative Visualisation                                  Shakti Gawain (One of the best 'positive thinking' books)

The New Diary                                           Tristine Rainer  (How to keep a creative journal)

Personal Development

I could do anything if I only knew what it was    Barbara Sher & B Smith

When is Enough, Enough?                               Laurie Ashner & Mitch Meyerson

Solved by Sunset                                          Carol Orsborn

Spiritual Development

Focusing                                                      Eugene T Gendlin (Excellent, tiny book about the power of                                                                                                     words)

Meditation

Moon over Water                                          Jessica Macbeth

Homecoming: Reclaiming and Championing your Inner Child            John Bradshaw

Banished Knowledge: facing Childhood Injuries                            Alice Miller

Bereavement                                                 

The Lovely Bones                                        Anne Sebold (fiction - to get in touch with grief)