Know what you want. Be as clear as you can about what kind of job you want. Visualize yourself doing that job and being happy in it. Nothing exists without first being a thought and don't be afraid to follow your passion. Make a list in order of importance of what kind of elements you want in a job. How far are you willing to commute? Do you want full time or part time? What is your ideal starting salary? Take everything into consideration, but also realize that you will likely have to compromise somethings in the beginning.
Begin job hunting before you graduate. Jobs aren't easy to find, especially in the current economic climate. Network through friends, social organizations you belong to, professors, alumni, academic clubs and sports teams. Put the word out about your availability.
Realize that college has not prepared you for everything. You must adjust to working with a team, dealing with all types of personalities, new demands in balancing your personal and professional life and new levels of pressure, not associated with school. You may have to learn new skills for coping with higher levels of stress.
Accept that your first job will likely be an entry level job, meaning hard work, long hours and low pay. Employers often want employees to experience all levels of the company or organization, to better understand the profession or business. Learn as much as you can about the company and key personnel. You may learn that it's not the right place for you -- a good fit is an extremely important aspect of easing your transition to the working world.
Manage your time effectively. College scheduling is very different from working 40 or more hours per week, and there is more at stake. In college, it was possible to have a late night social life and miss a class the next day. You can't do that with a job. College may not have taught you time management, so you'll have to learn how to schedule around your job, which is all about prioritizing.
Assume the attitude of a professional, once you have the job. College was a place where you could get away with dressing and acting a certain way, but the job atmosphere will be different. Whether you like it or not, you will be judged on your attire, your speech, your attitude and your motivation. Professionalism means being responsible, accountable, motivated, willing to go the extra mile, meeting deadlines, working with diverse groups of people, and being a team player.
Negotiate job offers, especially if you are lucky enough to have more than one. Go back to your list of priorities. Negotiate for things that may not have been offered. You have nothing to lose.