Here are two great articles I read via Cal Newport's Stuck Hacks blog.
Eliezer Yudkowsky writes a guest post about the planning fallacy at I Will Teach You To Be Rich. The message is very simple. There is no way you can estimate the amount of time a project will take by breaking it down into little details. (This statement is backed up by studies and data in the post.) The best way to estimate the amount of time is to remember how long it took for a similar project.
At a blog called "The Growing Life: Alternative Productivity, Anti-Hacks for Living," the author, Clay Collins, lays out his "alternative productivity manifesto." He tries to take down some common myths about productivity and bring us knowledge workers back to the reasons why we live and why life is worth living.