The definitive guide in my day (probably still is) was "DNS and BIND" from O'Reilly. It goes into excessive depth on the subject.

The short answer is this: a domain name doesn't get propogated around the Internet. When you query for a domain name, there is a distributed lookup algorithm, and a bunch of caching involved.

When people talk about domain name changes propogating, what they actually mean is that the cached information has expired, and that instead your PC will grab the up-to-date information from the original server.