Radio has changed since I started in 1990. Computers are heavily involved in the field now. Anyone interested in a career in radio should gain an extensive background in production programs and the most recent technology. Also, be ready to deal with egos that are larger than life.
With that said, I have enjoyed my jobs that ranged from disc jocky to morning sidekick. However, the salaries are not that large for the average radio personality. From what I've experienced, the better-known names seem to take a bulk of the advertising dollors. Yet, I've always enjoyed working in radio as it is always changing.
Radio DJ/Announcer Let's start with the upside, on-air can be a LOT of fun. No two shifts will be the same, and in the space of a shift you will get to communicate, educate, inform, and (hopefully) entertain--at the same time you're working with technology! You get a sense of satisfaction from fulfilling someone's request for a song and making them happy. Now the downside. The industry is changing due primarily to media consolidation but also due in part to new technology. For example you used to be a real "disc" jockey cueing your records (or at least CDs) and controlling your segues, now that is mostly gone since the music is coming mainly from hard drive. Finding and keeping a job can be VERY hard since there are now fewer positions then there once were. When you do get an entry level job don't be surprised if "they" hire someone literally off the street to do the same job you are doing (only it may have taken you college and/or experience to get there). Don't expect networking/contacts to benefit you--they probably won't. Don't expect experience to get you a promotion/job there will always be someone who will tell you that your experience is not relevant or is insufficient. So if you literally live for on-air and not "other" things (for instance money) being a DJ/announcer can be rewarding.