Connecting WinCC v 6 with OPC Server

Hello ;

I'm a begginer user for WinnCC and i have my graduation project on this package,

in my project i need to connect WinCC with OPC Server either the internal OPC Server on any additional software such as Kepware server.

I need a detailed information about configuring WinnCC to communicate with OPC Server and read tags from it .

and if any one has a simple application about this citeria , i will be very thankfull!!