Safely bringing Linux into an existing enterprise IT environment

How can I safely begin using Linux in an already existing enterprise IT environment?

Most organizations are finding that they already have some Linux somewhere in their operations as "edge" (file, print, mail, etc.) servers, or that these can easily become the first steps taken by many groups to safely experiment with Linux in their IT environments. Other organizations have gone further, or decided to take the plunge in one step, by developing/porting enterprise end-user applications to Linux, either on distributed or mainframe environments.

The skill sets required for these development and support activities are found in most organizations in their already-existing UNIX staffs and I have found that these people actually like the challenge of doing new work in this new platform.

Having a well-integrated project plan really helps ensure the success of these early projects.