I have a domain name and wish to transfer it and change the nameservers. If I change the nameservers do the files I current have get transfered to the new host or will they get deleted?

Do you want to transfer the domain name to a new registrar?

or

Do you simply want to change the nameservers?

Transfering a domain from one domain registrar to another, in and of itself, will not change the nameservers.

If you are talking about moving your domain to a new host and your old host is maintaining your DNS information, I suspect he will no longer do so.

No DNS information will be transferred automatically in any case. Your new host would need to manually configure your new DNS records for you.

You could always do this yourself using a third-party DNS service now, and then change the DNS information yourself when it's time to move - taking your host(s) right out of the equation.

-t

I'm changing my nameservers...

If you are just changing nameservers for a domain, define the DNS information in the new nameservers, and then change the domain record at your registrar to point to the new nameservers. Leave the old nameservers alone until all the propagation delays have completed - at least a week - then you can remove the old DNS information from the old nameservers.

-t