Every book you read will help you become a better domain investor. Reading books help you connect the dots and will help you as a domainers.
I read 2-3 books every week and these are some books that I felt were helpful in the domaining business.
So let us first Analyse this- What makes you a good domainer?
1) Being able to pick good names?
Classical books on Branding will help you understand what makes a good Brand.
The 22 Immutable Laws of Branding by Al and Laura Ries is a great primer on Brands. You can ignore the Internet business sections but the basics are still true.
If you are not very good in words, then The elements of Eloquence is a great read to understand 2-3 three word names
The Etymologicon is another good book on words.
2) Being able to understand customer psychology, and sales copy?
I like Thinking, Fast and Slow: Daniel Kahneman, Predictably Irrational by Dan Ariely, Ca$hvertising
Many more... Just reading books will expand your horizon and help connect the dots..
^^ This is a book that everyone should read. Will help you in all manners of business and personal finance.
I love these too.. Great books..