As a student, your best approach to finding a good job after you graduate is to figure out what kind of job you think you might like before you graduate, and then find a way to intern or volunteer in that kind of job. At worst, you can gain a few job skills, add another item to your resume, and learn some things you don't like, which is valuable knowledge. At best, your low- or no-pay position can develop into a full-time, well-paying job after you graduate. Either way, you win. (But don't work too many hours--no more than 20 per week if you're trying to be a full-time student; 10 is better.)
Even if you have no idea what you like to do, interning or volunteering is also a great approach to learning. Just pick something and do it for awhile.
In some careers, particularly specialized ones, you just have to learn where to apply. For example, psychologists with advanced degrees who want to work in psychology can consult the job listings at PsycCareers.com. Local students and grads wanting to work in mental health should consult at the Mental Health Workforce and Education Exchange: Bay Area, the Asian-American Mental Health Directory, or The Greater Bay Area Mental Health Education Workforce Collaborative.
For most careers, especially less specialized ones, the Career Development Center can be a huge help. They have job listings in many areas, and can help with the job search, as well as opening doors to internships and volunteer opportunities.
However, for almost any job, experts agree that the top source of job referrals has long been networking.
If you're looking for a job, tell everyone you know--family members, friends, acquaintances, teachers, classmates, co-workers, and even strangers whom you've just met at a party, on BART, in the laundramat, or in the unemployment line--that you're looking. Tell them what you're looking for and why you'd be good at it.. Work out in advance what you want to say. The better you're able to describe in a logical concise way what you're good at and what you're looking for, the more able your listeners will be able to keep their ears open for something that might be right for you. Referrals are often second or even third hand--your brother-in-law's friend's adminstrative assistant might hear about an opening from her husband--so encourage your acquaintances to mention you to their acquaintances. That's what networking is all about. Get some business cards to hand out to people so they'll know how to get in touch with you if something comes up. .
Obviously, job fairs are excellent places to seek jobs, but job fairs and professional conferences as well are also excellent places to build your network, so look for them, get your courage up, and go.
If an opportunity comes your way, be ready to respond quickly and efficiently. Return calls promptly. Have your resume in tip-top shape (the Career Development Center can again be a big help). If you're asked to send it, make sure to provide a cover letter addressed to the correct person, explaining why you're the right person for the job. If you get an interview, do it right. (Once again, the Career Development Center can help.) If you don't land that job, be ready for the next opportunity.
Whatever it is you start doing, don't expect to keep doing it forever. The career marketplace is always changing. To be able to keep up and advance, keep adding to your skill set. Ask for more responsibility and variety in your work. Getting a dream job may not be possible--any job involves compromise--but by keeping your network active and your skills sharp you'll eventually find a job you can love.