I have no programming experience (well, a tiny bit of C++ from college I have since forgotten). I'm somewhat interested in learning some languages so I could understand what's going on under the hood in Plex (and other things) and perhaps make some plug-ins eventually. What would be a good starting language? Are there multiple languages that are critical, or should I focus on one and dabble in others as I find the need? Recommendations for books to get me started would be very much appreciated.
Plex itself vs the plugin system require very different toolset.
Plex is C++ based. That’s the limit of my knowledge there.
For plugins, Python and XPath. Plugins are pretty easy to write once you have your head around them. The framework does most of the heavy lifting for you and allows you to concentrate on extracting the data and media you are interested in, rather than plumbing work of integrating with PMS. Certainly easier (for me at least) that attempting to extend Plex itself.
Another helpful one but not nearly as important, learn how to read javascript. A lot of websites have their support urls hidden inside of javascript that can lead you to hidden rss feeds and movie links.
Good choice. It’s always best to not get hung up on what language to use and to simply jump into one that is used in an environment you can learn from, one you will find use of for yourself.