How do you import/where do you put video clips?

Question

With my Windows Vista PC, video clips taken by my iPhone or digital camera were imported by Windows Photo Gallery and stored in the same directories as the photos. These videos could then be synced via iTunes in the Photo tab, when you selected a photo directory that contained video files and clicked on the "Include videos" box.
Now on my new iMac, I see the same "include videos" box under the Photo tab for any given iOS device in iTunes. But, iPhoto did not import even my iPhone-created videoes when I migrated my photo library.
So my question (i'm a mac newbie in case it was not clear): How do I need to setup the video import process so that camera and iPhone videos are stored in the places they need to be, so that they can be synced in iTunes during photo sync? Does iPhoto need to be configured in some way to import the video, or am I supposed to use iMovie to import video clips into a library which can be used by iTunes for syncing during the photo sync process? Or is there some other program I have to configure? When I connect cameras with video clips, my iMac is not bringing up any program by default to import the video - is there some sort of configuration option I am supposed to select?
Second question: I have a lot of video clips in avi format created by older digital camers. What format do I need to convert them to in order to get them into a format which can be imported into a library and synced to my iOS devices? Previously on my PC, I converted the AVI files to MP4 format, and it worked just fine. However, again iPhoto did not recognize these files (maybe if I get question #1 answered this will no longer be an issue).
Thanks,
JB

Answer 1

I guess the reason I like the iPhoto approach is that it arranges my photos chronologically/as events, which makes it easier for me to view. I also like that I can sync my videos by event. This workflow works for me because I have a tendency to make a lot of video and only get around to editing later, but often still like to look at the raw video from time to time. Meanwhile, I note that viewing clips in iMovie is far less convenient - clearly this is for editing only rather than viewing. So if I understood it correctly, to do it this way, I should convert video clips in iMovie to, I guess, the *.mov format and move those into iPhoto, yes?
I just took a video with my iPhone and confirmed that iPhoto did import it. However, I still can't figure out why iPhoto did not see the existing iPhone mov files in my PC photo library from the USB hard drive when it imported all other photos from the same. I then dragged and dropped some of those mov files manually into iPhoto, and this worked... but not well. Those videos got arranged as a separate event, and then I had to go and put them back into the correct event.
I have hundreds of photo subdirectories from the PC library, and I don't remember which ones have iPhone video files. Is there a way to search the entire photo directory for *.mov files and drag them from there into iPhoto? If I could then see the file name or time/date stamp of the individual mov files, I could then sort the mov files manually into the correct events.
What if I were to make iPhoto reimport from this photo directory, with the hopes that it would automatically pick up the mov files? Would I get duplicates of existing imports by this method?
Finally - am I correct in assuming that I only have to convert my existing avi video clips to mov format in order for iPhoto to be able to handle them?