Early in my command and I’m supposed to be preparing for a BN conference call…so I won’t go into too much.

Planning is critical and the hardest thing to do.  You need to have the foresight to look out months in advance and ensure key training resources are locked in.  To add to what @cale said, I force my TPU (m-day) Soldiers to be involved in the planning and execution of tasks.  But to accomplish that you must plan well in advance to provide flexibility to those Soldiers with other responsibilities and to ensure we can fund orders or some other duty status to bring them in as necessary.
Administration is the part of the job I hate the most, yet it yields the most noticeable results.  At least to my CoC which views my organization as a bunch of numbers.  Get to know the administrative processes and ensure your staff is maintaining quality control in the systems of record for things like flags, deployability codes, DMOSQ codes, APFT data, HT/WT data, medical readiness, etc.  The other big part of administration is the UCMJ and administrative separations.  Unfortunately, I’ve been dealing with a backlog of Soldiers that haven’t appeared in 2 years.  You need to understand the exact requirements the regulation has and what your command adds on to packets for separation.  A backlog of UNSAT/NP Soldiers will destroy all the metrics that your command probably uses to rate you.
Lead from the front is incredibly cliche, but it’s truly critical.  Do what’s right all the time and set the standard.  Don’t allow a previously lackluster command/leadership climate set the tone for your command.

On a separate note, I thought the book by Chuck Holmes was pretty good because it definitely hit most of the big topics.  What I didn’t like about it was the lack of details, specifics, and examples of ways to accomplish things.  It seemed mostly like it was “broad brushstrokes” over most topics.