I would say find a mentor. The most important learning is from other people's experience, watching how they work. There was one "old timer" electrical engineer I worked with closely as a firmware developer who mentored me to the point I was comfortable doing my own design work. You'll still want to read AoE, understand theory etc. but the practice of electrical engineering is a lot more than that.

EDIT: Also, not sure if this is still the case today, but I learnt tons from reading Application Notes. I guzzled application notes books from all the semiconductor manufacturers.