I still remember the first time I had to use a non-windows operating system. I couldn't make head or tail of how to navigate the file hierarchy. It was so different from the working of windows that I had to overcome a steep learning curve. But once I mastered the Linux way of working and its file hierarchy, I felt that it was (and is) a robust operating system and has very many advantages over the windows OS.
Jeffery.G.Thomas has writen an insightful article which details the ten things one should know about every linux installation.