Shell programming is a topic that every professional programmer should care about, and keep improving on, for several reasons. Here are the first two I can think about:

1. Because is essential in order to promote the automation of many manual processes (and automation is damn important!).
2. Because I like to be a programmer as much as a devop, and I want to be able to deploy what I develop, and take care of all the operational and system stuff related to the system I contribute to build.

Me myself made the mistake of underestimate the relevance of this topic for way too time in the past: don’t make my same mistake :-) Carl Albing’s “Great Bash” by O’Reilly Media is a collection of several short video lessons on the basics of the shell programming. I watch the “Great Bash” lessons hoping to learn more about shell programming, but unfortunately Carl Albing’s video lessons are too introductory (IMHO). It was nevertheless great to recap many things I learned here and there, and so my time watching it was not wasted at all, but I would recommend this video only to shell programmer beginners. There are also some (really) minor defects in the technical way the video is recorded: the audio quality may be improved and sometimes the speaker take some long inexplicable pauses. But, that said, the overall quality is really good. In the end I recommend to watch this video if you are a shell programmer beginner and you want to start understanding more about this topic.