The ! bit bucket five things to know when you switch to Linux:

#1: App-searching is a pleasure, or: How to install and uninstall programs
#2: Be wary when going root, or: The command-line and the root user
#3: Two (different) sides to a coin, or: GNOME and KDE
#4: You-may you-may-not, or: File permissions
#5: Five more quick tips, or: Various additional details

-No defragmenting needed( file systems in use are extremely resistant to fragmentation )
-Anti-viruses made redundant
-Case-sensitive filenames
-Hidden files start with a dot
-Accounting for hardware (i386)