Start your job hunting process at the end of your junior year. First place to go is your school's career center. If all things go ok, you should have an offer, or better yet, offers by your last semester. That is what I suggest. I personally did not start looking for job until the latter half of my senior year and regretted it. I could've done better had I known what I said above. Nonetheless, I was lucky because I went to a good school and we had a very good career center. I managed to get a job two weeks before I graduated.