Lindeburg has done a great job at pulling together everything you'll see on the PE Mechanical exam. The format of the 12th edition is better than the 11th. The 11th included extra problems at the end of each chapter. Though this is helpful for studying, it clutters up the book and adds extra pages to thumb through during the exam. Edition 12 moved the problems at the end of the chapter to another book ("Practice Problems for the Mechanical Engineering PE Exam" - which I also recommend).
The book isn't perfect. You will find errata. Most of it is covered in the errata sheets on ppi2pass. Take an hour to look at the errata sheet and transfer the corrections to the book.
All in all, if you read each chapter and then work the associated practice problems, you should be able to pass the exam. The nice thing about this book is the fact that it is up to date with the exam. This is not true of some of the review classes you can take. I paid $1,750 for a class at Renssalaer in Hartford. I should have just taken the money and flushed it down the drain. The class was out-dated (the teacher kept giving examples of problems he remembered from when each question was 1 hour long). He also kept teaching us subjects and then saying "You probably won't see this on the exam". Talk about a waste of time. Also, the class claimed that the Lindeburg book was the official text. It wasn't. The official text was a 3 ring binder full of the teachers barely readable (they were copies of copies of copies of copies....) notes. Anyway, enough ranting about that. If you want to take a class, make sure you talk to someone who's taken it before, and make sure it teaches out of the Lindeburg book.
Also, as soon as you start studying, buy an approved calculator. It will be your best friend during the exam and you will need to be 100% familiar with it. Use it every day and get use to its functions. I have the Casio fx-115 ES. It served me well during the FE exam and the PE exam. Also, buy 2 of them. You must have an identical spare! You don't want your main calculator to die during the exam and then try to use a calculator you found laying in the bottom of your junk drawer. It will slow you down if you're not 100% familiar with it.