+1 for multiple sources. I've yet to find a single source that is clear and understandable across the board. Switch between sources when a topic seems to be unu

+1 for multiple sources. I've yet to find a single source that is clear and understandable across the board. Switch between sources when a topic seems to be unusually difficult to understand. Then go back to your original, favorite source. Note that I do not think this applies to books that simply showcase and act as a more advanced reference of programming languages. Those are normally plain enough, I think. For others subjects, like math or CS, multiple sources have always proven invaluable for me.