BPO Setup, Sharing call centre facility

We are in the process of setting up our BPO centre, preferably in NCR area. Looking for consultants / vendors, who can help in setting-up. Any pointers to reading material / websites would also be helpful.

Call centre will also be part of set-up. So, also looking for a possibility for buying an exisiting small call centre, or sharing telecom infrastructure with existing call centre.
Any pointers / direct contacts / suggestions would be of great help.

Thanks in advance,
Amit.