I recently finished an excellent book on why we procrastinate by Neil Fiore called "The Now Habit". What I really like about this book is that it doesn't give you the usual slogans for fighting procrastination ("Just Do It", "Man Up", etc..) and instead talks about the way we humans are wired and why we procrastinate. There are a variety of reasons. For some of us it is a defense mechanism, others are afraid of success. We all have our own groups of hang-ups. Either way, he goes deep into these motivations and allows you to dig yourself out in a way that is both enlightening and uplifting. I strongly recommend the read if these things interest you.
There was also a good article posted this morning at GetRichSlowly.org that is a little less cerebral yet still helpful. My favorite tip there is "Don't Multitask". I really think anyone that multitasks on purpose is making a mistake. Just do one thing at a time. Do it right. Anyway, you can check out the article right here.