14 Ways to Acquire Knowledge: A Timeless Guide from 1936 by Maria Popova is a great read.
Here are a few fragments from the original post. There is a lot more to read and reflect upon.
If you must read in order to acquire knowledge, read critically. Believe nothing till it’s understood, till it’s clearly proven.
To know it — write it! If you’re writing to explain, you’re explaining it to yourself! If you’re writing to inspire, you’re inspiring yourself! If you’re writing to record, you’re recording it on your own memory.
To learn, experiment! Try something new. See what happens. Lindbergh experimented when he flew the Atlantic. Pasteur experimented with bacteria and made cow’s milk safe for the human race. Franklin experimented with a kite and introduced electricity.
If you would have knowledge, knowledge sure and sound, teach. Teach your children, teach your associates, teach your friends. In the very act of teaching, you will learn far more than your best pupil.
Animals have knowledge. But only men can reason. The better you can reason the farther you separate yourself from animals.