Hey dude,
I have just opened a call centre, it has taken me two years to find a viable contract before it made any money at all, until now we have been loosing money every month without fail and I still haven't got the 10's of thousands of pounds back that I put into it! This is not an easy thing to do and unless you have thousands of pounds that you are willing to loose I would probably look at something else.. A few of my friends have also tried to open them and failed miserably, loosing all their savings!
ps if you do continue with it, never trust the indians or filipinos asking for money up front to introduce you to their clients who have lots of call centre work! They take your money and run every time! I have not been caught by them but my friends have!
Good luck,
Danny