The interface is very intuitive and the website offers different webinars which explain step by step how to start creating your own presentations and to make them more and more complicated. Prezi has recently added a tool which allows users to import their previous power point presentations. To sum up, a very interesting tool to work with and share presentations with other educators. It can be very useful for students to create their own projects.
More information about prezi: Here. The tutorials are also available in youtube:
Once you create your own account you will have access to many presentations that can illustrate all the possibilities this program offers. If you prefer to have a look a one presentation without creating your account, here is an example.