I started to read Zen Habits about 3 years ago when I discovered my passion for personal productivity and self development after I had read various books from David Allen (including Getting Things Done) and Steven R. Covey (especially The 7 Habits of Highly Effective People and First Things First). Although I have lost a bit of interest in Leo’s thoughts lately (although I read his book and found it pretty good), the classic Zen Habits posts are still a source of inspiration on its own. So in case you haven’t read them for a longer period of time or not at all, go and revisit http://zenhabits.net/2008/07/the-beginners-guide-to-zen-habits-a-guided-tour/. It’s really great.
I especially recommend 20 Things I Wish I Had Known When Starting Out in Life and The Unsurpassable Productivity List. Revisit them on a regular basis and try to learn from the mistakes others have made – it will safe you time and energy for the important things. For those of you who have already implemented GTD or another productivity system, read How to Actually Execute Your ToDo-List – it can be an eye opener for real productivity junkies (like I was once).