I recently published an article on Inc.com saying that people who read are going to be a mile ahead of those who do not. I received a lot of feedback from aspiring entrepreneurs asking where they should begin. After I gave myself some time to think, I listed what I believe are the five best books for beginners or veterans.

Constant learning is key. Finding ways to carve out enough space in the day to dedicate to reading is the difference between a hobbyist and a successful entrepreneur. 

When studying the habits of successful people, I continuously came across one thing they all had in common: They are well read. Successful entrepreneurs are at their best when it comes to time management and squeezing in a meaningful amount of reading time in their schedule.

Not long ago, I visited the office of a very successful client. I looked over the books on his shelf and the ones on the desk (the most recently read), and made a mental note of them. If I knew nothing else of the man, the books he read created a clear portrait of his personality that no LinkedIn profile could outdo. My respect for him increased, simply on the basis of the books he read.

The right book has to have that balance of facts and stories, inspiration and actions, and somehow leave you changed afterward.

Here is a list of five of the books that I recommend to every entrepreneur.

1. Think and Grow Rich by Napoleon Hill

You should have read this book at least once if you're reading this article. If you haven't, you should shut down your computer, go buy a copy, and read it. Don't come back until you're done. This book is the original source of the "law of attraction": that what you desire most is what you will achieve. I tend to get so caught up in the busywork of running a business that I forget why I'm working! This book teaches me that if I have that constant goal in my mind, I will achieve it.

2. The One Thing by Gary Keller

Do you know who you are? What makes you successful? Those are the questions posed by The One Thing. If you can't identify that one thing that makes you unique or valuable, this is the book you need. This book taught me how to analyze myself; when I finally broke myself down, and discovered that one thing that makes me me, I was able to ignore  distractions, and I became more profitable.

3. Manage Your Day-to-Day by Jocelyn K. Glei

"Stop doing busywork. Start doing your best work" is the theme of this book. Many times I have met inspiring entrepreneurs, and creative geniuses, who are kept from amazing success because of their terrible schedule or lack of routine. I was guilty of the same thing. No amount of talent or skill was able to help me until I created a manageable schedule.

I used to always run to fix the latest "fire" in the office, and I would get nothing of value accomplished all day. When I come in with a ready schedule, not only do I generate more value, but I also get more done, and things end up resolving themselves.

4. Traction by Gabriel Weinberg

Successful companies aren't the first ones to the market. The best startups aren't the ones with the most original product. (Ask Myspace, Yahoo, or Vine.) Startups rise and fall on the traction they have at operational levels. You can have the best idea in the world, but if your production process is garbage, you'll never make a dime. Traction is the easiest way to bring your company in line with your goals. It's the CliffsNotes version of running an effective business.

5. Mastery by Robert Greene

Success isn't about what you know; it's about who you are. Take a true leader from any industry, and he or she could find a way to succeed in any other. Why? Because the traits necessary for success aren't limited by college degrees and don't vary across industries.

Mastery will teach you what these traits are, how many you have yourself, and how to develop those you lack. And once you master yourself, the rest is easy: You can master any industry or any market. Mastery is a book I return to time and again to remember what the traits are, and then I realize something I've overlooked. Once I put it into practice again, it's almost magical how my business corrects itself!

Whether you're just starting a business or are a longtime veteran, there are business difficulties you will face. You need to take the time to read. From classics to newly released titles, books are something every entrepreneur should find time for.