Thanks for the suggestion.
This could be done with Foolcat, an application that I use for my RED footage (R3D files), but since a while it allows for Quicktime as well.
It takes three stills [start, mid, end] and can either produce a HTML or an pdf.
However, with the amount of tutorials currently available that would be a huge list. It might be advised to separate those in themes. Perhaps even along playlist collections.
Just my two cents.
All the best