Please elaborate the topic you want to know.
you can have a look on the SRND which gives you an overview of almost everything about the application you want.
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cust_contact/contact_center/crs/express_9_02/design/guide/UCCX_BK_C39FDB35_00_cisco-unified-contact-center-express/UCCX_BK_C39FDB35_00_cisco-unified-contact-center-express_chapter_01.html