Syncing (at least at our amateur level) is usually done by alligning the waveforms in the soundtrack.
I take it when you were miming, you were miming along to your recordings and you recorded the sound on the camera, yeah? (If not, now is probably a good time to go back and do it again or it's really going to be painful trying to align audio & video)
You won't use the sound from the camera in your final video, but you will use it for allignment.
SImply drop your video clip on the timeline which will create a video event AND an audio event.
You will already have your "proper" high quality audio on another audio track.
Now it's simply a case of lining up the peaks and toughs of the audio from the camcorder with the peaks and troughs from the main audio.
Look/listen for sharp staccato sounds (rim shots etc) which will produce a very short peak and line these up.
Searching? Like Google, it takes a bit of practice to get the "feel" for what works best. Can't give you any pointers other than that I'm afraid.