There are numerous technologies associated with Call Centres today.
The main ones being
CRM Customer Relationship Management an all singing all dancing idea that takes the call from the point of entry regardless of medium(e-mail fax telephone voip) right through to the back office.
MIS Management information systems for stats etc.
IVR Interactive Voice Reponse which takes away mundane tasks from agents
CTI Computer telephony integration for the screen pops and integration to existing legacy systems such as Databases etc.
UM Unified messaging which integrates e-mail, fax and voicemail on the users pc.
MOH Music and Message on Hold systems to make use of the time the customer is in Q.
The list goes on it is advisable to visit some manufacturers sites such as http://www.lucent.com as their white papers are usually very good.
Hope this helps