The i2b2 Installation Guide contains detailed information about setting up the i2b2 in your environment. The installation of the i2b2 Web Client is addressed in Chapter 5.1. i2b2 Web Client Install.
The i2b2 Admin Module is part of the web client and is used by administrators to setup and maintain the i2b2 environment(s). Documentation on setting up the i2b2 Admin Module within the client is in Chapter 5.2.3. Admin Module Integrated into Webclient
Chapter 14. Initial Setup of i2b2 in Admin of the i2b2 Installation Guide contain additional information on setting up the Admin module in your environment.
i2b2 v1.7.13 now supports SAML authentication. Details on setting this up can be found in Chapter 8. SAML Setup for i2b2.