PowerPoint projects should be well-crafted and professional, and about 25-30 slides in length, with narration or narrative text as part of the program itself (and not simply presented, for e.g., as presenter's notes in a powerpoint presentation).
Your narration can be voice-over or textual
You should have captions where appropriate
The "narration" can be pretty straightforward. It is the "story" that links the slides together
If you look at any of the slide sets from the first part of the semester, there is a set of word slides linking together the various images
(Note, as mentioned above written "narration" should be part of the program itself and not simply presented as off-slide notes in a PowerPoint presentation. That is, the PowerPoint "show" itself should be self-contained. The same priciple is also true as it might apply to a web page presentation.)
As with any presentation, it is good to have a beginning, middle, and an end. Usually the beginning contains what in writing they call a "thesis statement."
The minimum format should be slides with information on hour project, with relevant illustrations. You may, of course, experiment. (But avoid items flying around and appearing randomly.)