The Appendix was the best part of the book. It had "memory hooks" much like "the principal is my pal".
There's a chapter for each letter of the alphabet. At the start of each chapter, there is a list commonly misspelled words. That was useful for me. The rest of the book, not so much.
This book is basically a paper version of Google. There are two columns, with the Incorrect spelling on the left, and in bold font, and the Correct spelling on the right, in normal font.
I think it's meant to be used this way: You look up the way you think the word is spelled (which is probably wrong), and it shows the "Did you mean...?" version, the correct spelling. The common misspellings have such odd variations though that it made me think "Surely people can't be this stupid?"
This book might be useful for places without Internet access or Autocorrect.
UPDATE: Brainstorm! If you have the EPUB version (or PDF would also work, I guess), CTRL+F is your friend.