I have to admit being biased towards this book due to my relationship with the author. I grew up knowing Skip Ross, my family is well acquainted with his family, and I've heard the "Say Yes to Your Potential" seminars numerous times.
While I haven't read this book for awhile, seeing it listed here encouraged me to pull it off my bookshelf and reacquaint myself with it. For personal success, the principles are timeless. As Skip says, "they work whether you believe them or not". He relates them to laws of the universe. Even if you don't believe in gravity, it still works. Your belief doesn't change it.
That's not to portray him as an egotistical author. He simply communicates the ten universal principles that he's learned through years of study and life experience, not ideas that he's created. Skip's life stories are interwoven into the book, as well as many other personal stories and experiences that add power to the message.
This is a great book. If you can find it, it's well worth reading.