The XNAT user documentation describes common tasks for PIs, study coordinators, image uploaders, and users in general.
The XNAT API provides a multitude of ways for users, administrators and developers to interact with XNAT.
All the details you need for hosting, deploying, securing and maintaining your XNAT instance at whatever scale you need.
Sometimes a dedicated tool is the best fit for a particular job. Here are the ones custom-built for XNAT.