Whether you're starting out in real estate investing or you've just closed the deal on your third apartment complex, there is always more to learn. In fact, having the humility and curiosity of a lifelong learner is a big part of what separates the successful from the unsuccessful in this (or in any other) industry. Here are some book recommendations that are definitely worth your time. Happy learning :)
Robert Kiyosaki
This book is the quintessential starter for entrepreneurs and will get you thinking! A modern day classic and perennial favorite of real estate investors (though no real estate specific).
Robert Kiyosaki
Kiyoasaki reveals how to work less, earn more, pay less in taxes, and learn to become financially free. Again, not necessarily real estate specific, but an important step in your understanding of building wealth.
Gary Keller
An easy read with content focusing on the theory and methodology behind great real estate investments.
Spencer Strauss
This book teaches you how to take a modest sum of money and invest in one property at a time to build a real estate portfolio. This is an exceptional beginner guide.
Larry B. Loftis
Loftis explains how to buy multi-family properties on a part-time basis to build wealth. Some of the lender requirements have changed significantly since this was written but the principles are rock solid.
Ken McElroy
This book will help you think beyond single-family/multi-family investments and make you want to buy an apartment building. It focuses more on big projects but again provides solid, basic investing expertise.