I've shared Cal Newport's blog here before but wanted to point something specific out about it.
Make sure you check the sidebar at the right under the heading, "Looking for Help on A Specific Problem?" There, you'll find his blog posts categorized into subjects like, "Fighting procrastination," "Note-taking," "Organization," "Studying," "Test-taking," and "Time Management."
Some of his material is dense and takes awhile to get through. But if you apply the tips he gives you, I think you'll find his advice is always helpful.