Found in 1 comment on Hacker News
The first is the Millionaire Next Door. Gave me a better idea of how to manage my finances and what kind of spending habits to look for in a partner. If you are a tightwad then don't marry a spendthrift. Vice versa. [http://amzn.to/2vAmbW8]

The second is On Writing Well. This book changed my view regarding how to write and how important it is to write well. As an engineer I regret how much I avoided writing in school. Now I play catchup after realizing lawyers and others with client facing jobs write much better emails. [http://amzn.to/2vTXu27]

And here are three other books that would be recommended by few on HN.

The Life-Changing Magic of Tidying Up: The Japanese Art of Decluttering and Organizing. I used to hate going home until I realized the clutter of stuff made me miserable. [http://amzn.to/2wwvS5h]

Why Men Love Bitches. 100% serious. This book is over the top but I stopped being a doormat in relationships and looked for partners with more self confidence. [http://amzn.to/2wwcYeZ]

The Low Down on Going Down. Yes the title is cheesy, but again I am 100% serious. I think a lot of us have unhealthy expectations due to Internet porn and this book sets the right attitude for the physical component in a relationship.[http://amzn.to/2vTSY41]

And companion book: [http://amzn.to/2wwSpyY]

Fresh book recommendations delivered straight to your inbox every Thursday.