Once you set up your mic, test it out with many tries before recording for good. Test different distances from your mouth (if you're wearing a headset, your mic should still be flexible enough to find a good spot), test what happens if you turn your head, and find a place where there will be the least amount of "noise" from your mouth (popping p's, sibilant s's, and so on).
Many a beginning podcaster has been horrified to hear herself spiking her levels as she says p's and s's. The hiss of sibilant s's has actually caused us to stop listening to some podcasts, as it can be literally painful to hear. To avoid this, try these tips: