Hey all, I'm new here, and I'll start by sharing something I've learned in the past year.
Depending on the content, the internal mic on your camcorder may or may not be sufficent. Outdoors usually in close proximity with people under normal situations (family gatherings, interviews and the like) the internal mic may be more than sufficient.
In other cases, like when I shoot video of for my friends band, I find the mic is just too wimpy. Nothing ruins the audio track like when the source is too loud and maxes out the mic's ability.
I was stuck with a camcorder that did not have a jack for an external mic. What was I to do? Well, some testing and I found out that my girlfriend's laptop's mic-in was actually a line in and supported stereo. I quickly found a reasonable mic for 60.00 online and proceeded to record the next events audio in uncompressed wav format using DBPowerAmp.
In Premier I was now subject to syncing the audio to the show. Using the camcorders audio I managed to sync it up at the beginning but after about 5-10 minutes it was a fraction of a second off. In this case I was lucky as there were good break points near the end of each song. Using that I managed to sync the whole audio to the video.
Someday I'll think about the investment in some kind of multi-track recorder and edit audio back at home into some kind of master. But for now, my ear is just too unrefined and the cost is somewhat preventative.
Also house recordings can sometimes be a good find, but one place made one for me and I realized it was before any extra effects like reverb were added to tracks and I was stuck with a single track of everything just slapped together. It was unanimous that is sucked.