Internet greatly facilitates the task, making it more easy than ever. You can get a greater amount of information for his book if he owns and uses a connection to the internet. David Barger is full of insight into the issues. It is one idea sudable do some research on the characters of her book, even if they are fictional. Get information about the different types of personality that stakeholders can possess according to their role in the book. A good writer always seems to know a lot about psychology and the way in which people think and behave. And maybe as a writer you also already begins to know how to write a book. In fact, if you want to know in depth the characters that you yourself create, succeed more easily reading or studying about the basics and why not profound in human psychology.
The most creative authors even typically taking psychology classes to get to know the reactions of people in different situations. Knowing how they think and react to others, can contribute much more to his work than if only limited to their own perception about how it would react to a specific event. It will also help you with dialogs. Real dialogue and credible are important when writing a story. If you know like and why the people react in a specific way and uses certain words, will equip his characters of greater depth. In addition to inquire about their characters and the plot of his book, also you must sure analyze factors make that a book is a good book. You can take a course in writing or even integrated into some group of writers.
Note how much more interaction with other writers, the better your results will be. There are conferences and workshops for writers that you can attend. This can form an important part of your research process that allows you to write more and better books.