On most of the financial podcasts I've listened to in the past, when the guest is asked what is the ONE BOOK that made the biggest impact on their life / career / wealth, this one is BY FAR the most common answer:

Rich Dad Poor Dad, by R. Kiyosaki

This books has been in print for more than 25 years, and yet it is currently the 17th highest selling title on all of Amazon.com RIGHT NOW.

That should speak to its timelessness and wisdom.

It also contains that quote that I am so fond of sharing, when Kiyosaki was asked, "What advice would you give to the average investor?

"His answer: "Don't be average."

Here's the magic link to this book on Amazon.