I found the following books to be useful and interesting, so thought I would share. I discovered whilst reading them that the author, Steven Pressfield, was also the author of The Legend of Bagger Vance which became an awesome movie starring Will Smith.
The War of Art
Break Through the Blocks and Win Your Inner Creative Battles
ISBN : 9781936891023
Tap Your Inner Power and Create Your Life’s Work
Do The Work
Overcome Resistance and get out of your own way