Did you ever wonder where the caboose track should be? How about a RIP or Tie-Up track? How long should the Drill Track be? What about arrival and departure tracks? This book covers them all with, plenty of photos and illustrations to show you how it's done in the real yards, and how you can mimic that on your layout.
As good as this book is, there's a website called "The Ten Commandments of Yard Design" that is also indispensable for good freight yard design: http://www.housatonicrr.com/
I recommend using this book and that website in conjunction with each other to obtain the best results.