I think that "The Secret" and such ilk is pretty silly but two books I have read are "The Power of Full Engagement" and "The Power of Story" both by Jim Loehr. I guess they would qualify as self-help books, but they are a lot more practical than what you usually see. "Full Engagement" basically just talks about learning to manage your energy instead of your time and discusses strategies for increasing physical, mental, emotional and spiritual capacity.
I like it because it applies a similar stress-recover-supercompensate model to building qualities such as patience as well as physical stamina. "Power of Story" is basically 200+ pages devoted to the idea of figuring out your goals, being honest about your actions right now, and figuring out what you need to change to make your actions match your goals.
I thought it was a little long-winded, but it was only like $5 more to throw it on the Amazon cart with "Full Engagement," which came highly recommended. I definitely recommend that one to anybody.
I think there are some "self-help" products that are useful, just like there are some good strength training books. However, it's less a matter of some magical method and more a matter of understanding principles and then actually applying them consistently and with hard work.
Ultimately, most people don't want to actually work to make a positive change in their lives, just like most people don't want to actually work to make a positive change in their bodies.