Have you spent any time going through either the TBB tutorial (available with the distribution and from the website) or James Reinders' book on the subject? The thing that I note in quickly looking through your website that there are a lot of details explored that should not be necessary for a beginning user to be concerned about, details that would be of more use to someone intending to actually modify the library.
Much of the material on functors should be old hat to anyone familiar with the Standard Template Library. If our tutorial materials are still set too complex for new users to make sense of, we'd certainly appreciate that feedback, and with specific examples of content that you were not able to follow. Our goal is to give everyone the tools and background to be successful in parallel programming; if we're falling short on that task, we'd love to know how to make it better.