Just learn how to think. The best way to learn to think is to solve many problems. Solve many problems many times. Don't just solve the ones you already know how to solve.
I am not sure you can learn how to think from a book, but the recommendations here can be good to "know what you don't know."
Maybe the best question you should be asking is not what to read, but what problems you can solve you have not solved before. Here is one constraint: if you can solve it yourself, and not through others, then it is not a very interesting problem.
Comments
Just learn how to think. The best way to learn to think is to solve many problems. Solve many problems many times. Don't just solve the ones you already know how to solve.
I am not sure you can learn how to think from a book, but the recommendations here can be good to "know what you don't know."
Maybe the best question you should be asking is not what to read, but what problems you can solve you have not solved before. Here is one constraint: if you can solve it yourself, and not through others, then it is not a very interesting problem.