One book that I would highly recommend to ALL coaches, in fact I would recommend to anyone and everyone is "Getting Things Done" by David Allen. It is one of the best time management books around because it delves into ways that we can become more organized and more productive. Coach Don Meyer turned me on to the book years ago and it has had a great impact in my ability to orchestrate my day.
Here is a short video of David going through just a couple of things that he shares in great detail in his book in terms of keeping his office organized.