Do consider the time it will take for your customers to comfortably work with the Linux interface. Just make sure they know the processes are still the same.
Do take advantage of Linux built-in security configuration utilities.
Do use the command-line interfaces in Linux, which are scriptable and easy to use in management and monitoring Linux.
Do take advantage of Linux GUIs that can aid in the configuration process.
Don't go into a Linux server migration without doing some research. Make sure your customers have the materials needed to adjust to the change from Windows to Linux.
Don't remove Windows before checking Linux hardware driver availability.
Get more detailed
Windows-to-Linux migration dos and don'ts at SearchOpenSource.com.
This was first published in January 2007