This website, from the Self-Development Center at the Counseling and Student Development Center of George Mason University, offers more time management tips and a survey of how students spend their time.
Most students report dissatisfaction with their ability to concentrate: they may have trouble getting down to work in the first place or feel that they never work as efficiently as they would like. While it is impossible to concentrate 100% of the time, it is possible to minimize external distractions and to begin to work on internal ones. This website from The University of Waterloo offers tips on improving concentration.