When people start working with a new system, most will immediately start clicking around and exploring - and continue that mode of use as a way of learning the system. This occurs despite the availability of clear, well-written documentation, much to the chagrin of technical writers everywhere. This tendency is known as the paradox of the active user. It’s a paradox because in the long term users would perform more efficiently if they invested time up-front in learning about features and functions.
While we still advise clients to provide help for their applications (users will refer to it if they get hopelessly stuck), we also look for opportunities to provide small bits of help that won’t completely interrupt a user’s task flow. An example of this comes from Adobe Lightroom, which provides a brief introduction to the basic areas of the interface when the application is first launched (click to see full-size images):
What is likely effective about his approach is that gives just a bit of information that supports users’ "clicking around" mode of learning.