This is what I learned: Adding a video clip to a UThink blog is easy!
I uploaded my video into MediaMill (http://mediamill.cla.umn.edu/), then I created a derivative--I chose "UThink, Small." The copy generated has an "Add to UThink" link that automatically places my video in the UThink blog that I choose. I could also access the html code from the "HTML Embed Example" link and drop it in that way.
One caveat--my video can only be accessed locally because the video itself is stored on MediaMill. If I want to upload this as a video podcast and create an RSS feed, then I need to upload the video to UThink instead of using the UThink link. I think I'll give it a try.... Lauren