Much has change in the last twenty years. Thirty years ago, you would need to buy a book or to borrow a book to study something. But now, everything is different. You can probably afford an Internet connection.
You are not able to read all the public Internet. There is so much websites.
Consider Maven, for example. Maven is a tool in Java used to build Java application and to resolve the Java application dependencies (on another Java libraries.
I tried to search maven using Google. Google claimed to have found about 65,300,000 results. This is a big number.
Please, take into account, if you do now know (I did not know clearly once): Internet (you will probably use Google) gives you very often too much websites containing some information about the area, you are going to study. Nobody (you also) is not able to process too much information.
You must know, that you will use only a small part of the sources available for the area, you are dealing with.
The good thing maybe is, you can study the same area many (many) times using texts created by different people. This may help you to study, if you will read the same thing hundred times. I see this aspect as a big advantage.