My 20c, start coding. You probably have at least a rough idea of how it works. Coding a proof of concept (POC) is going to be a great way to see how things fit together and work at dev and run time. Reading will only take you so far, doing will really help make it click.
If you don't know where to start, most blog posts about DI have simple examples that you can run up. Don't get stuck on which framework to use (Unity, Spring, Castle Windsor etc) because it really doesn't matter for a POC.