Martin Lewis of moneysavingexpert.com has written a book called ‘ The three most important lessons you have never been taught’ where he talks about the three most important lessons which are:
Lesson one: A company’s job is to make money
Lesson two: Debt is not bad, bad debt is bad
Lesson three: Loyalty does not pay
Although you can buy the book and it will teach you a lot, he also has a free e-booklet on the website which expands on the above principles.
You can get access to the free e-booklet here.
I hope this is useful.