The Richest Man In Babylon by George S Clason is one of the classic books on building wealth and is standing the test of time due to it's straight forward and commonsense aprproach.
Commonsense is not necessarily common knowlege and I think it's fantastic to continue to relearn these simple things.
He are the five laws of gold which Arkad, the wise, rich man gave to his son.
1. Money comes to those who save.
2. Money multiplies for those who invest it.
3. Money stays with the person who entrusts it to wise people.
4. Money is lost when invested in things with which you are not familiar.
5. Money is lost at a fast rate by pursuing get-rich-quick schemes.