FTB - Moving House - Where to start?

Ok we have completed today, and moving next friday

I think you mean you exchanged contracts on Wednesday, and are completing on Friday? That's when you'll get the keys. (Congratulations! ;D)

Now can we change Gas/Water/Elec suppliers straight away.

I don't see why not, once you've moved in and got an account number(s) from the existing supplier(s).

also where is the best place to get hold of all the quotes.

I've used www.uswitch.com when I've changed suppliers in the past.

Another thing, what happens if i get old bills from the previous owner, i don't have to pay these do i?

Make sure you take meter readings when you move in, and give them to the existing supplier(s). If any bills arrive for the previous owner, forward them on (if you have the person's new address) or return to sender, and maybe phone the company that sent the bill to double-check that they know that the person doesn't live there any more.

Martin's article about this subject is here.

Good luck with the move!
Dan