bind 9.3.2 and split dns

[fybar]

I think that split DNS is the correct term.  I have a FreeBSD server acting
as a firewall with IPF acting as a DHCP server and I want it to also be the
DNS server.  I want to configure it to serve internet DNS as well as
provide dynamic DNS for my internal lan.  Is there a tutorial on how to set
this up?  I imagine that this is a common config.  Is there an example
named.conf somewhere that shows how to do this?

Thanks,

fyb