Also, Kirupa.com, Flashkit.com, and the inbuilt tutorials in the Flash program itself.
Another thing that can help is replacing "flash" with "as3" or "as2" when searching. Since the programming language in Flash is Actionscript (Actionscript3 is the current iteration, AS2 is used for Flash Professional 8 and below), you can search "as3 button tutorial" if you specifically need help with the coding part.
most interactive videos using flash, will either be one long video which employs embedded cuepoints, or else the video will be broken up into its relevant sections
bare-bones workflow for cuepoints:
event cuepoints are embedded where you want something to happen - the video stops, buttons appear, or othere means of interactivity becomes possible when the video player hears that event cue point be reached. the buttons/interactivity is coded for your choices. based on that, it would either continue play or jump to another section via emebedded navigation cue points.
the video is broken up into sepearate videos for each section. at the end of each section ( on reaching completion of that video) buttons or other things appear to allow for the interactivity/choices to be made. depending on the answer/request, the next relevant video is loaded and the tutorial proceeds.
as sam says, there are many tutorials out there, but it is best to search more specifically: as3 cuepoints, etc
and of course, feel free to ask us more specific questions too!