Document, document, document. Make sure that everything you have completed, everything in process, etc is clearly documented and your team is on top of what their responsibilities\tasks. Also make sure your team is aware of the hand off of the project and go through at least one meeting with the new PM and the team, just in case there are questions. If the person you are handing off to has good documentation the hand off should be pretty seamless.
What do you think is the most important things to be documented? I have a contact list and action items. What's the easiest way to hand off? Like if we run a meeting together and then the next PM just runs with it?
I recommend you shadow with the transitional PM for a week - having them attend meetings with you to get acquainted with the team, status of the project, forthcoming tasks, documentation, etc. Then do a formal hand-off with the transitional PM where you answer any questions (s)he may have and they take control of the project documents and monitoring/controlling of the project work. In your documentation, defintely include: charter, project plan, roles and responsibilities, financial info/management plans, risk management plans, and any other relevant project documentation the transitional PM may need going forward. Of course, make yourself available in the future as well should (s)he need historical project documents.