Question How do I record with two microphones on my camcorder?

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Hi friends.

I am an amateur with camcorders. I have some intermediate experience with graphic design and with the recording and editing of music, but not with video editing. I am trying to learn fast how to do both filming and editing. (I have two laptops, one is a PowerBook G4 and the other, a Sony Vaio. The one has iMovie, so I think I will be editing with that, for now. With only 2GB of RAM and a 2GHz processor, I don't have much to work with. I am open to using Windows as well.)

In fact, I am in the U.S. on vacation, but I live in South America. I will be going back in ten days, and wanted to buy the camcorder here, to take back and use it there.

Three weeks ago I bought a new Canon HF R500 with only the very basic accessories, and now I need to know which additional accessories to buy--especially the microphones.

My main interest is in recording conversations between two and three people, to demonstrate certain aspects of conversation, persuasion, argumentation, question-and-answer techniques, and other things, mostly using a rehearsed dialog. I hope to edit the videos, shorten them, and present them together with my power-point teaching presentations somehow. (Until now I have been using only text and photos in my presentations, and I am making the videos in order to enhance the program with a little visual variety).
I will eventually be adding subtitles and background music, but nothing much more sophisticated than that, for now.

My main question for now is how to record the voices well when I film.

I understand that Hollywood films typically overdub about 80% of the dialog in a recording studio, because of issues with background noises and so on. I would rather not have to do this myself, if possible, particularly since a little background noise will not detract from my purposes, as I will try to emphasize the dialog but not the "cinematography," the sets or the acting. I suppose that I could clean up the "audio track" of the video (if that is what it is called) using external audio-editing programs, and perhaps feed it back into the video after that? I would rather not have to do that either.

My first proposal for the audio was to use three little pocket-sized digital recorders, with 1/8" lapel microphone attached to each subject. I have already bought them but not used them yet. I was thinking of transferring the individual voices this way, to my video-editing program, to keep each sound separate and more editable. Looking back, I think that this may require much more work than I had expected.

Someone else suggested that I buy a shotgun microphone for my Canon HF R500 camcorder. As I looked over the descriptions online, however, I was concerned that such a microphone might require too much "focusing". In other words, as I will be filming at a distance of about six feet from my subjects, when one fellow spoke, I was worried that the camera/mic might have to be pointed more directly at him; and when the other spoke, my cameraman would have to point the camera/mic toward the second man. Am I right about this, or can I just point to the space between the two of them and hope for the best?

My other proposed solution for the audio was that I somehow plug two wired microphones into the camcorder simultaneously. My camcorder has only one mic jack, however. My question, then is, if this setup is possible, what kind of microphones to use, and what kind of Y-adapter would I use?

Anyway, any suggestions that you can offer will be greatly appreciated.