Where to start...having open conversations with your developers is a great place to start. It turns out we love studying and talking about our field.
If you don't have ready access to developers, you can try reading through "Coders at Work" that I linked to at the bottom of my post. Another great idea is to just go to Wikipedia with any of the terms you don't know.
Codecademy or things like it might teach you a little more about a specific language, but these are general principles that are not dependent on a given programming language. This is more about software engineering as a discipline.
You might also try "The Agile Samurai" by Jonathan Rasmusson. I've never personally read it, but it's in our office and I didn't hate what I saw in the table of contents.