Reverse DNS

[Brenda A. Bell]

Can someone point me to a good resource for getting a better
understanding of reverse DNS and the role it plays in the big picture?
I understand dig and use it frequently, but I'm trying to get a better
understanding of my current DNS setup, why things work the way they do
and whether my config is acceptable.  I'll explain:

I have a permanent IP address I got from my ISP.  When I dig my ISP's
nameservers for my IP, I get a PTR record for
111-195-35-64.mcttelecom.com.

I have a small network from which I host a web server and and an email
server.  I don't particularly want to (or need to) run a full-fledged
DNS on my own network, so I use ZoneEdit.  While I only have a single IP
address, I have entries at ZoneEdit for my domain, my mail server and my
web server.  This is where I start to get a little confused...

A dig against my ISP's nameserver for my reverse IP address gives an
authoritative answer -- makes sense since it does own the address and it
has the PTR record.  A dig against ns1.zoneedit.com for my domain name
gives an authoritative answer.  A dig against ns1.zoneeedit for my
reverse IP simply refers me to the root servers.

I don't see evidence of any problems occurring because of this setup,
but I remember reading somewhere that your RR's should be correct in
order for you to be considered "clean"... at the same time, I can't
imagine that my scenario is uncommon given the number of people who run
small home setups like mine.

Some good references or opinions on the subject would be most
appreciated.

Brenda