I think the answer to this question will depend on what sector of real estate your are interested in. I think real estate is not just one asset class but multiples asset classes. I believe many people start in real estate without a complete knowledge of the economics behind it, sites like Bigger Pockets will have a lot of information directed to new investors and their podcast will give you tons of ideas. I have being using what they call BRRRR (Buy, Rehab, Rent, Refinance, Repeat) it is great to grow your portfolio but you need to be careful because it is a leveraged strategy.
From the mindset point of view and without the entrepreneur background I find "The Wealthy Gardener" the best book I read, everything else I think you can find it on internet.