John Weigley has an excellent video on using Magit. It’s very comprehensive and the content is quite dense so you may want to watch it more than once. He covers the usual easy commands that everybody uses but also some of the more esoteric commands that you may not even know existed. Certainly, I learned a number of commands I didn’t know about.
Rather than provide a content list for the talk, here’s a link to the Org notes for the talk. You may want to download that first as it makes following the talk a little easier. The talk is long (an hour and 18 minutes) so you’ll need to schedule some time. If you’re a Magit user or think you should be one, you definitely need to watch this video.