Here's a wonderful webcomic about sustainable creativity by Stephen McCraine. It has some great insight and perspective on procrastination and finishing projects.
Start From the Beginning
How to Fight Procrastination
How to Deal with Failure
How to Move Towards Big Goals
Also, he's doing a Kickstarter to make a physical book version: http://www.kickstarter.com/projects/stephenmccranie/brick-by-brick