CRM order and SD Biling

Hi,

I am working on CRM implementation:

The scenario is " an order document is created in CRM and billing should be done in ECC 6.0" can any one help me what needs to be configured in SD of ECC 6.0.

Upto order creation it is stand alone, at present i am able to create order in CRM but nothing has been configured in SD, now billing should be done in SD. Anyone plz suggest, will reward maximum points.

Thanx