What a distribution is. Some of the ways that distributions differ. Source-based versus binary distributions. How to choose a distro. The difference between distributions and versions.
The structure of Linux
The virtues of simplicity. The kernel and the shell. Unix utilities. Helpful daemons. The X server and the graphical desktop. A wealth of window managers. Libraries and how programs use them. Applications — the programs that work for you. Why it would probably not be possible to write a chapter entitled "The structure of Windows"
File ownership and permissions. The root user or superuser. When and how to become root — and when not to! More security; the pam system. Why Linux viruses are exceedingly rare. How Linux encourages you to explore your system and learn to understand it — and why Windows doesn't.
The Linux file system
What are all these weird folders?
Windows — a largely undocumented system. Linux documentation: man pages. Linux documentation: info pages. Other local documentation. HOWTOs and the Linux Documentation Project. More information online.
Software packages and package management
Installing and updating software in Linux. Where software comes from: repositories. Package managers. Dependencies: what causes them and how package managers handle them. How to build software from source if you have to. Upgrading and removing packages.
How Linux empowers its users. Problems with programs. Using the system logs. Solving problems. A case study.
Appendix: Twelve lies about Linux