Cura is developed by Ultimaker to make 3D printing as easy and streamlined as possible. It includes everything you need to prepare a 3D file for printing and to print it. Cura is fully preconfigured to work on the Ultimaker. Cura comes with a friendly setup program that help you install the latest firmware as well as calibrate your printer.
The latest version for Windows, Mac and Linux can always be found at the Ultimaker software downloads page.
Main documentation for Cura can be found at Ultimaker: User manual