Now that my BIND installation appears to be handling internal queries correctly, it's time to bite the bullet and open it up to the external world.

Advice I received earlier in the piece said "Until you open port 53 (TCP and UDP), to external traffic and
delegate your domains to your name server, there is no effect on
external lookups for your domains." Now, I understand about port 53, but I don't understand the part about "delegate your domains". What do I need to do here?

This might be related to something I've never understood about nameservers. How do I tell the world that I'm running a nameserver? Presumably the nameserver for the org. TLD needs to know about pmoylan.org, but how does it find out?

Also, I'm guessing that I need to leave my previous nameserver hosting in place for a day or two to allow for propagation delays. Is that right?