This is a pretty good article from WikiHow:
"Graphic designers are responsible for creating notable product logos and/or packaging designs that will catch the public's eye and increase a company's sales. To be successful, designers must also possess excellent interpersonal skills and the ability to sell their ideas to executives.
Instructions
* STEP 1: Take drawing courses while you're in high school.
* STEP 2: Be prepared to receive a college degree in fine arts or advertising with concentrations in graphic art and computer graphics.
Although it's sometimes possible to work as a graphic designer without having a degree, much of your competition now
graduates from college.
* STEP 3: Visit the National Association of Schools of Art and Design Web site (nasad.arts-accredit.org) to compare the offerings of schools
in which you have an interest. Make certain they offer training in current graphics-related computer technology and that their
electives include business and finance courses.
* STEP 4: Contact your top school choices to see if they require samples of your artwork along with an application. Be prepared for a
possible interview.
* STEP 5: Get an internship in the design department of a company near your college. It will look good on your résumé, and you might
make valuable career contacts.
* STEP 6: Do freelance work whenever you can so that you will have a solid portfolio to show prospective employers when you graduate.
* STEP 7: Pay attention to packaging designs and advertising trends in all forms of media.
Tips & Warnings
* Be prepared to contact employers for interviews, even if they have not posted classified ads.
* Make certain your portfolio showcases only your best work.
* This is a career in which about 1/3 of the individuals are self-employed. You may need to be constantly on the lookout for your next job,
especially during the early years.
* Expect to work long hours when a project is nearing its deadline.
http://www.ehow.com/how_16304_become-graphic-designer.html