You've probably done some research already, but it always pays to be prepared. Get to know the organisation from the outside, the who, where's and why's. Where they fit in the sector or industry you work in and their position in the marketplace. Who their partners are and any significant achievements.
Sounds obvious, but it's definitely worth making sure you fully understand what's expected of you and what you bring to the new job. If you have a clear picture of your roles and responsibilities, you can start to plan to avoid any bumps in the road. Speak to your line manager as soon as you can. Confronting anything that sits out of your comfort zone early can fill you full of confidence and protect you from the trepidation of unexpected demands.