First things first

Stephen R. Covey et al (First Things First)
Stephen R. Coveyoffers a categorization scheme for the hundreds of time management approaches that are on the market today.
First generation: reminders
Devotees of this approach limit their time management efforts to keeping lists and notes. They see these papers as reminders. Items that are not done by the end of the day are transferred to the next day's list in the evening.

Second generation: planning and preparation
People in the second generation use calendars and appointment books. They will note where meetings are held and identify deadlines; this is sometimes even done on a computer. As opposed to the first generation, the second generation plans and prepares, schedules future appointments, and sets goals. This in turn saves their time.

Third generation: planning, prioritizing, controlling
Third generation time managers prioritize their activities daily. They use detailed forms of daily planning on a computer or on a paper-based organizer. This approach implies spending some time in clarifying values and priorities.

Fourth generation: being efficient and proactive
Stephen R. Covey, in his book First Things First, refers to his approach as the 4th generation time management, and stresses the difference between urgency and importance in planning. What are the most important things in your life? Do they get as much care, emphasis, and time as you'd like to give them? Far from the traditional "be- more- efficient" time- management book with shortcut techniques, First Things First showed us how to look at our use of time totally differently. Covey teaches an organizing process that helps you categorize tasks so you focus on what is important, not merely what is urgent. First you divide tasks into these quadrants:

Quadrant Activities
   1. Important and Urgent (crises, deadline- driven projects)
   2. Important, Not Urgent (preparation, prevention, planning, relationships)
   3. Urgent, Not Important (interruptions, many pressing matters)
   4. Not Urgent, Not Important (trivia, time wasters)

Quadrant Activity Examples
Most people spend most of their time in quadrants 1 and 3, while quadrant 2 is where quality happens. "Doing more things faster is no substitute for doing the right things," says Covey. He points you toward the real human needs--"to live, to love, to learn, to Leave a Legacy ( Publishers Weekly)
For example: some people may go their entire lives completely missing out on important things (like spending time with their children before they have grown up) because it was never "urgent." The point is not to ignore urgent things, but to embrace important things without waiting for them to become urgent.
The results of properly dedicating ourselves to Quadrant 2 activity are that we will gain control over what is happening in our lives: we will thereby reduce the time we spend in Quadrant 1.
Time for Quadrant 2 activity, of course, must come from Quadrants 3 and 4; minimize or eliminate the time you spend here.

Another way at looking at the 4 quadrants is examining the results from each quadrant.