If you use LR, Camera Raw, and or Photoshop, get it. It is far and away the best book yet that I have come across about the 'digital negative'. It lets you understand not only a process for working with digital files, but a lot of the theory behind what happens and why. Mr. Schewe is hands down, the authority on pretty much all of the digital process. Plus, it is written in a very down to earth, friendly, easy to read style.
I highly recommend it.