Staff Development Resources
Professional development makeup: 10% external training (conference etc), 20% internal training (workshops, documentation etc), 70% learning by doing
If you read only one, make it that one. All the nuts and bolts of middle management.
A bit weird and old fashioned, told as a kind of business fable, but a really useful frame of reference for thinking about how work flows through a business. Jeff Bezos gets his execs to read it. (note: there's been a lot of advancement in this field, so treat this as primer not final word)
Again told as a weird business fable, really solid framework for thinking about a leadership team above and outside of a managers operational team. Interesting quantitative data supporting the model out of the games industry
If you want to get really stuck into reading more business/management books this is a must read. Highlights a lot of the logical/cognitive fallacies in most business writing - helps sort wheat from chaff.