Comment by Desafinado

It's good to have solid hands on experience in a variety of languages and platforms, ideally either from college or a handful of different jobs. Without that it's harder to learn on your own time, and you'll be better served by spending time building things (if you have the time).

If you're already a solid developer with a breadth of experience then read widely. Just keep reading, take notes, save your notes. Studying software architecture over the long-haul will offer the most return of any topic.