Remember it is the radio show of the host/hosts; not your’s. You are a guest so let the host appear knowledgeable about your subject matter. If you are working with a host who you doubt has a good grasp on your subject matter then email them, at least 48 hours in advance, a list of topics you feel will make good radio topics. Explain the topics you are presenting are what most people are interested in when they contact you. If you are new at this game the terms “most people” might be your family members, doesn’t matter as the bottom line is you know what you present well better then anyone else. By the way my experience has been that 90% of the time the radio host will feed me at least a few topics/lead-ins off the sheet I sent them.
Radio time flies by so keep the topics to something an audience, who can’t see you, can feel coming through the airwaves. Part of this will be based on your energy, part on the energy coming from the host back to you (so the host is your “reflector” of sorts.) Don’t get off into areas that are esoteric, you won’t have time to make a full case and you aren’t delivering a summation to a jury. Keep it to easily understood concepts about who you are, what you do, what your product/service will do for the audience.
Make sure to interject your website, contact information, at least a few times in the interview. Can’t begin to tell you how many radio interviewers forget to tell the audience more than my name and never get around to the website address more then once. Website address should come up at least once every two to three minutes during a radio interview. Also, if your radio host will link your website to their website (some will, some won’t) that is a “win win” for you both!