You need to have a college degree, but not necessarily in journalism. Many journalist minor in journalism and then major in a specific field that they may be covering. For general coverage, a degree in English, history or political science is often helpful. However, many newspaper, television stations, etc. are looking for people with a science background or technology background who can explain new developments in these fields. With all the economic news today, a degree in business or economics would also be valuable. The secret is to major in a field you like and minor in journalism. Then, when you are a junior or senior in college--or beforehand if you can manage it, be sure to write for a school paper, report for a campus radio station or TV station and/or get an internship at a local news outlet. Many of the people I knew who got good jobs in journalism right after graduation were great interns, who made no money during their internships, but impressed the editors who hired them after they got their degree. Finally, any conference you can attend where there will be professional journalists you can meet, attend. This will give you a chance to introduce yourself and let them know you are interested in working in the field. Oh, and don't forget to keep a notebook or portfolio of your work for all potential employers to see. Good luck!
The most important thing is to have great speach abilities and good writing skills. If you still can join the debate club and/or school paper on your last semester; this won't only give you experience, but also looks great on a college application. If you can, be sure to take a creative writing and news writing course during the summer. This will help you be ahead and familiarized in some writing concepts you'll need to have developed for your college experience. Also, think about taking a photography class while in college or before you enroll. Usually, colleges have their own newspapers having the extracurricular experience in school and a photography course may help you land a job in the college paper which will give you further experience and you may qualify for financial aid programs the journalism school may as well have. You may find this article to be of help too: http://www.journalismcareers.com/journalismquestions.shtml. I hope this all helps you. Good luck!