I purchased a website & since I'm returning to work I want to sell it. The seller is not responding. How can I get the necessary info (whois, hosting company,etc) so after I have a buyer I can transfer it? Note: he stated in a post-sale email that I cannot sell it and that he has a ghost script on it.

I'm not sure I understand - it sounds like you purchased a domain, but the original owner hasn't tranferred ownership to you yet? If that's the case, I surely hope you didn't pay this person yet. You have to be very careful when buying domains and I would typically recommend using a domain escrow service (unless of course the sale of the domain was for a nominal fee), in which case you simply need to trust the seller.

You can do a simple whois on the domain to see who the currently registered administrator and owner are. This will also show you the primary and seconday DNS hosts. Go to www.internic.com and type in the domain name you are looking for.

You can find all of the important info by doing the whois search at either http://www.networksolutions.com or http://www.godaddy.com or any other top level registrar.

You can try using http://www.dnsstuff.com/ 's WHOIS lookup.