There was some talk on AUTOCAT recently about LC genre and form headings. Though I tend to head to the Online Audiovisual Catalogers online site, I just learned that OCLC has a web session that you can play or download for free on LC genre/form headings. Even if you missed the originally streaming version (May 3 or 12, 2011), this is a handy reference. The web session is an hour. The presentation, by Linda Gabel, introduces genre/form headings in terms of definitions, sources, or how to search for genre/form headings. This material is introductory. If you are already familiar with genre/form headings, I would skip this presentation.