From the reaserch I have done you get few if any Sky channels (assuming you ever get it at all).
The only sky channels you may get are free ones that are available on Freeview such as Sky News and maybe Sky 3.
You certainly WONT get Sky 1, Sky Movies or Sky Sports etc.
I get the impression the people who phone you up will say anything to get you to sign up, even promising sky channels.
As I said in my prevous append NEVER agree to anything that is offered over the phone, there are some nasty people out there who will take your money for doing nothing.