sound quality? (easy, I'm a noob!)

First post, I hope I get one free pass for a noobish post.

I’m aiming to use Audacity to record a podcast that will be pretty much a music radio broadcast: song after song, with some voice-overs and recorded bits in between and on top. First test run, I took a phone message, “hey, I’m so and so and I listen to djeddieo…” I was quite happy with my ability to chop up and rearrange that message, then I laid it over the opening seconds of a song. It sounded okay (I played it back in iTunes), but not half as good as the song alone sounds. The song’s at a 44.1 kHz sample rate while the voice clip’s at 8.0; iTunes says the song+clip is also 8.0, even though in Audacity the song’s at 44.1; is there a way to change the sample rate of what I export as mp3?

***please go easy…I’m analog!