Ancestry.com has done some work recently organizing its instructional videos at YouTube. They now have a very useful Playlists page. This groups their videos (and there are a lot of them) by topic. For example, there’s a Genealogical Proof Standard playlist containing Crista Cowan’s six GPS talks, and another on AncestryDNA.
A group I haven’t seen before is called 5-minute Finds. This includes a video
just uploaded last month: Exploring the Ancestry YouTube Channel. If you’re new to YouTube and/or Ancestry, you should watch at least that one.