I decided to make a list of books I felt were useful to anyone no matter what profession they go into. This is just my list and is not to attempt to list all of the greatest books, just books I feel have the most practical information.
This title is about as clear as you can get as to the book's intentions. I think any profession, and personal relationships can be aided by this book. It may sound like it is about how to manipulate people but it's more about finding ways of mutually benefiting, or just how to make someone feel important. The advice in this book if used by everyone would make the world a better and more pleasant place to be. Aside from that it will also likely help you get what you want and understand better what other people want.
The Bible
Whether you are Christian, another religion, or atheist, this book is a must read. Now the term must read may make it sound like a page turner, which it is most definitely. It's more as if the pages were glued together it's so hard to get through, but if you are Christian, you should really know where all your beliefs come from. If you're not, you should know what a huge percentage of people base their faith on, and it is referenced so often in other books, tv, movies etc... that you need to know it to understand what they are referring to. I'm sure everyone has heard the term something "of biblical proportions" and its good to know exactly how big those proportions are. (I thought I needed to mention as a side note, I am an atheist so please don't take this someone trying to push their religion on you.)
The Seven Habits of Highly Effective People by Stephen R. Covey
This is another book which will be useful to you which ever field or career you decide to take. It's mostly a book about managing tasks in you life, and deciding the most important tasks to manage. There are probably other books that have similar advice but this is the one I've read. I don't follow his exact system of organizing things, but knowing how he does it has been very influential in how I created my system. I personally think no book will have the perfect way to do things, everyone will have their own tweaks which will be better for them, but more important then how the system works, is that you at least have some system in place. This book is a good starting point.
Any good book on nutrition
There are so many out there, and I'm sure some are better than others, but you should read at least one. Knowing how what you put into your body affects you is very important. When I read the symptoms of certain vitamin deficiencies I recognized them in me or friends and family. Everyone has a different diet and you may realize you don't happen to eat anything that provides a specific vitamin. Knowing what comes from where you can alter your diet or take supplements to correct anything you are lacking. I would venture to say, feeling good day to day is the most important thing in life and knowing how what you eat affects your body, along with exercise, is the best way to feel good.
Cosmos by Carl Sagan
This book covers so much information in a wide variety of areas, it's worth a read just for that. Some of the most important historical events, scientific discoveries, and greatest men are written about in Cosmos. I can't give a specific reason you should read this book, but I can assure you at least some information learned in this book will help you or inspire you. A History of Knowledge by Charles Van Doren is another book similar to this. It's explores the most important discoveries mankind has made and how they were made. Ever wonder how we know what elements the stars are made out of when they are light years away? The answer is more straight forward than you might imagine.
The Ego and the Id by Sigmund Freud
Freud is one of the first men to really start treating the mind as a science. While many new theories have come out since and our understanding of how the mind works has increased, reading Freud is like reading Newton. We know Einstein replaced Newton's theories of gravity but if you use Newtonian formulas they still work 99% of the time. His theories on how the mind works are insightful and very interesting.