Do you mean, for example, when someone has to talk for twenty or thirty seconds before going to a live interview or commercial? I’m not positive what you’re getting at, but it’s probably a better question to ask someone like fishbicycle, who works in the commercial radio industry. Play the songs, take requests, remember to give the weather forecast every so often, and try to get the commercials played somewhere around the half-hour - that’s about the extent of my on-air responsibilities. 
Yes; in fact, I have two lined up tomorrow. I forgot to mention that I also do a second show at CFCR, called “The Afternoon Buzz,” where I read off music and entertainment news, play brand new CDs that have just arrived (literally - the mail arrives sometime around 1:30 PM, and I go on at 2:00), and occasionally interview guests.
Interviewees could be local musicians performing around town, out-of-town artists in for the weekend, authors, acting troupes, pretty much anyone. I once arranged an interview with my ex-GF, who was sponsoring a province-wide protest of tuition fee hikes at the University of Regina. One of my questions for her was whether, during the protest, she was going to sack the parliament buildings and burn them to the ground.
I sort of answered this in response to digs’ question, but again, it’s probably that I get exposed to so much new and exciting music volunteering there. That, and I can discuss stuff like the merits of Ben Gibbard’s work with Death Cab for Cutie compared to his 80’s electro-pop collaborations with Jimmy Tamborello as The Postal Service without feeling like I’m speaking in antediluvian tongues.
Oh, and nerdy music girls who host radio shows are invariably cute. That’s a perk. 
Yup, we got a station, I’m think the frequency in 91.3FM. I listen to it from time to time, but it’s mostly playing indy rock, punk rock, hardcore rock, some jazz, pop, pop rock, rap, R&B… as far as I know, there is no classical music show on the station.
Unfortunatly, I don’t really have the time to get into it, but I’m asking you really how much work one has to do to begin with. From previous replies, you state you don’t need a huge technological knowledge base, so I’ll take that for granted :). Anyways, thanks for the help earlier, I’m still considering a radio job if I can get into the business.
klockwerk, here’s my two cents:
I also have a degree in music, and for about a year I worked as a board operator and announcer at a PBS station where I did late night jazz programming, occassional classical music announcing (as a substitute announcer when the regulars were away), and periodic news, along with standard station breaks and promos.
Although I was knowledgeable about music, I’d say my biggest challenge was the accurate pronunciation of foreign composers and the titles of their works. For example, how well would you do with the following: “Claude Debussy’s L’après-midi d’un faune was premiered on May 19, 1912 by the Ballets Russes in Paris at the théàtre du Châtelet.” (And believe me, people definitely notice and call in to tell you when you’ve done it wrong). If you’re not naturally adept at this, I’d recommend you do a lot of careful listening to professional announcers, and practice what you hear. I’m not sure of a good class to take to learn this, but perhaps a diction class that vocal music majors take might be helpful.
But this won’t be much of an issue if you work at a station that does indy rock, punk rock, hardcore rock, some jazz, pop, pop rock, rap, R&B, where your on-air personality will be more important.