Almost a month ago, I completed The Artist's Way workbook. While I'm not doing my morning pages anymore, I'm using that time to write--more frequently and confidently than before. For a writer making a return to regular word counts, this book was an incredible help not only to get back into the practice of writing, but in figuring out why, for example, the idea of sitting down to write made me anxious.
Even if you don't do the full workshop with daily pages and artist dates and all the exercises, picking and choosing those bits that resonate with you can be beneficial.
If you're curious about the 12 week program, Julia Cameron has an outline on her website: http://juliacameronlive.com/the-artists-way/