2. Figure out what classes you'll take. Once you've decided on a major, get organized. Figure out what classes you'll need to complete your major requirements in four years. Get your general core requirements out of the way first. Talk to your advisor to help form your four-year class plan. Once you've created a plan to graduate in four years, check in with your advisor at least once a semester to discuss your progress. Some classes are harder to get into than others, so sign up for them as early as possible to secure a spot. If you followed your graduation plan and run into trouble getting into a class that you need to graduate, you may be able to appeal to the department head.
3. Take at least 15 credits per semester. Take enough credits each semester so you can complete your graduation requirements in four years. This usually turns out to be around 15 credits per semester. Don't drop classes. If you fall short, make up the credits right away -- either over the summer or during a winter session. It's not enough to sign up for courses worth 15 credits; you must do well enough in them to pass or you won't earn the credit.
4. Look into four-year guarantee programs. Some schools have four-year graduation guarantee programs. These programs, like the one at , require students to pledge at the start of their freshman year that they are committed to graduating in four years. Students are often required to declare their majors during their first semester and agree not to change majors. The school agrees to make this happen by providing advising resources and facilitating registration. See if your school has a program like this during your first semester on campus.
With a little planning, you should have no problem earning your degree in four years.