Hi just wanted to know, have setup my machine as a ftp server, so people can ftp to me directly, was just wondering at the moment I signed up for a free dns service (no-ip.com) so instead of someone ftping to an ip address they can remember a name address to ftp to.

My Question is what if I already have a free domain name, can I use that and what do I put down as the domain name servers, do I put my ip address down?

You need to setup a DNS server, no-ip provides this but not for free.

You should go to www.zoneedit.com they offer free DNS and ip forwarding. If you have a domain you just change the name servers to the ones specified at zoneedit.