Where can I find lists of businesses for me to sell my product to?

thegrape

I am an IT Business who has just become the Sole Uk resell for a piece of software. I really want to target IT Support companies and software houses with this product but as I am used to only marketing to the general public this all a little bit new to me.

I know that you can 'buy' lists but I am always very dubious of them and am sure there must be a cheaper way to get them?

Any IDeas?

Debt_Free_Chick

Dun & Bradstreet spring to mind, but there will be others too. D&B's website is here