you stay away from any high definition camcorders. Your G4 iBook is just not up to the task.
As I recall, iMovieHD '06 was the first version that could deal with HDV format video from miniDV tape camcorders. The stated hardware requirement included minimum CPU is a G5. As I recall, the Flip UltraHD shoots 720p high definition video into Video format: H.264 (.MP4) files. In a Mac with a G5, this would be a relatively slow import/decompress process. With an Intel-chip Core Duo based Mac, it is a relatively fast import/capture/decompress process.
The JVC Everio GZ-MS110 Flash Memory Camcorder will save ".MOD" standard definition video files. iMovie cannot deal with these files directly. The MOD files need to be transcoded (converted) to a file format iMovie can deal with - typically MOV or (standard def) MP4 or DV files, then imported to iMovie. (This is not much different from Windows MovieMaker which prefers WMV files).
is a good transcoder. There are others.
Other consumer camcorders using flash memory (or hard disc drive) for video storage generally save standard definition video files to either MOD or MPG format. The transcoding step will be needed for either file type if you continue to use the iBook.
I *think* iBooks were manufactured through about 2001. At that time, the best video storage technology available to consumer camcorders was miniDV tape. (In my opinion, it continues to be the best storage technology available, but that is not what this discussion is about.) The Canon ZR960 is one of the few entry-level consumer grade camcorders available. In addition to its built-in mics, it has a mic jack - which most consumer camcorders do not have. You will want to use an external mic for improved audio quality on your vlogs. Connect a 4-pin to 6-pin firewire cable to the camcorder's DV port and iBook's firewire port, put the camcorder in "Play" mode and iMovie can Import or Capture the video from the tape. There is no firewire cable in the box with the camcorder and USB will not allow importing of the video from the miniDV tape - the cable is inexpensive.
Are there any recommendations for a decent camcorder that is compatible with the old iBook G4 (Mac OS X 10.4); mainly for uploading YouTube videos and possibly vlogs? I have been looking at the Flip UltraHD and the JVC Everio GZ-MS110 Flash Memory Camcorder. I like the idea of having a screen to look at, since I'm an amateur; plus I was able to find the MS110 for less than $150. I wasn't sure of how much I liked the Flip UltraHD; it is rather small and may not be as conducive for the types of videos I would want to shoot (mainly videos of me creating artwork). I would appreciate any recommendations or input that you have on either of these cameras, or other models. Thank you.