NSU (Northeastern State University) posted a well-organized SciFinder overview.
The UAkron (University of Akron) tutorial on Research Topic search tips is particularly well thought out.
Campbell University library's How To Use SciFinder video is older but still valuable.
Baylor University Library has created a small series of videos on different SciFinder search features.
Chemical Abstracts Service (CAS) has created a quick slideshow on key features of SciFinder's search interface.
CAS also creates SciFinder tutorials, some of which focus on specific database functions, for example:
Searching for References [pdf]
More tutorials are stored on the CAS Training page.
The CAS training materials usually consist of self-paced slideshows or videos.