Success in college takes more than brains -- it takes time. College work requires a lot of independent learning. You will need to schedule time to go to the library, write up lab reports, meet with professors, and take care of other academic business. Compared to high school, you will be spending few hours in class; 12 to 16 hours a week is typical. However, you will be expected to spend twice that much time preparing for each class. For example, if you are taking 12 credit hours, you should plan to spend 24 hours a week on homework. Twelve hours of class time, plus 24 hours of homework time equals 38 hours devoted to school each week. This is the equivalent of a full-time job!
In college, completing assigned homework is just the start and is often not enough to ensure success. Professors expect you will do whatever is necessary to master course material. This means going above and beyond what's assigned. Use your weekly study time wisely: recopy class notes, make and study flash cards, or create sample test questions. Getting involved in a study group is also a good way to make friends and test your knowledge. Have regular meetings with professors to keep track of your progress. By investing time each week, you can keep grades up and reduce stress at exam time.
So while you are planning time for eating, sleeping, and having fun, be sure to schedule enough time to prepare for class.