For financial books, I have a couple that I recommend that I think everyone should read as a good foundation for finances.
1.) Rich Dad, Poor Dad by Robert Kiyosaki - this one goes into detail about how to think about your money correctly and the important of owning assets over liabilities.
2.) The Richest Man in Babylon by George Clason - this book talks about the importance of paying yourself first and shows you how it works
These two books I think are fundamentals. I am sure that list will grow over time but there are still many books I need to read. One book I am currently reading called The Secrets of The Millionaire Mind by T. Harv Eker will probably be another one on my list of favorites once I finish reading it.
Some books that are not directly related to finances but I believe are important to read for someone taking finances seriously are:
3.) How to Win Friends and Influence People by Dale Carnegie
4.) The Go-Giver by Bob Burg and John David Mann
These 4 books have completely changed the way I view certain things in life such as finances and have really helped me in becoming a better person.