This is just one opinion, just like rear ends, everybody has one and (most) stink in comparison...
1) Not discouraging going to school for broadcasting. However, in today's world you may be better off getting a minor or take a few broadcast/recording arts classes and focus on a different major. A lot of folks who see you fresh-faced with a newly printed degree in broadcasting will tell you "You wasted your money" as they feel the time spent in classes could have been spent doing entry-level radio work. They're not right, but they're not wrong, either.
2) Start off at a community radio or college radio station. If you can, avoid using a computer to play your songs...try to get them on CDs so you can get used to seguing between pieces. It helps you develop your style of broadcasting, gives you a crash course in basic FCC regs (profanity, legal ID, transmitter readings) and primarily helps you feel comfortable with the pace of radio. On top of this, learning how to properly run a station "manually" (that is, without the help of a computer) will earn you a little extra respect amongst the old grizzled radio-types.
3) Learn as much as you can about the station where you "work" (or volunteer). Be prepared to work extra hours to do this properly. Even if you're, say, production director (person who makes commercials and some imaging), see if you can talk with the sales/underwriting folks. Learn how they do their craft. Above all else, get to know the engineer or some of the technical folks. These are the folks you call at 11:30pm when the automation computer locks up or the transmitter mysteriously shuts off. While you may not learn all of their job, learning enough to help yourself out of a sticky situation technically can help you earn the respect of the engineering staff and on-air folks (who will probably recruit you to do as much engineering work as possible). On-air folks and engineers rarely interact beyond what is professionally neccessary...not always true, but more often than not the case. Basically, you want to know enough information to make you more valuable than the next guy/gal. Enough info to be "dangerous".
4) Have fun! Realize that in order to make a career out of radio, you gotta take the good with the bad. You may move to three different cities in less than a year, may get fired for no other reason than the station is flipping formats and you were a warm body to occupy a seat for a few months. There may be several months where you are out of radio work...hopefully, that's when your other skills come into play. While other jocks will eat into savings or take an entry-level hourly job to pay the rent and car bill, you will have a second career as a backup.
My situation put me into a position where I was out of paying radio work my senior year in college after 8 years of working radio for a job. I picked up a job in hotels and didn't go back into professional broadcasting. However, fast forward 10 years, I have an awesome job and I'm doing radio as a hobby: Right now I'm lending my assistance to the engineering commitee of a LPFM out here that's starting up. As a tech geek like myself, there is nothing more fun than building your "own" radio station!
Lastly, you will find many bitter people who used to or still do work in this industry in some way, shape, or form. Take what advice you can from these folks, but filter it. Most people become bitter due to poor life choices they made that now come back to haunt them.
Good luck, and welcome aboard!
Radio-X