I have a dedicated server and I want to have a reseller account. Is there away I can have something like NS1.RESELLERDOMAIN.COM point to NS1.MYDOMAIN.com? How would I do this? Thanks

Each nameserver needs its own IP address. If you have multiple IP addresses bound to one DNS server, you can assign different nameservers such as ns1.mydomain.com, ns1.resellerdomain1.com, ns1.resellerdomain2.com, etc. for each of the IP addresses for that server. The BIND server (or whichever DNS server you have installed on your system) should accept queries on all IP addresses on your server.