Documentation and tools.
Real Documentation exists. Online and in print. The reading of several of these is required to make the step from small time DNS admin to a big time one. In print the standard book is DNS and BIND by C. Liu and P. Albitz from O'Reilly & Associates, Sebastopol, CA, ISBN 0-937175-82-X. I read this, it's excellent. There is also a section in on DNS in TCP/IP Network Administration, by Craig Hunt from O'Reilly..., ISBN 0-937175-82-X. Another must for Good DNS administration (or good anything for that matter) is Zen and the Art of Motorcycle Maintenance by Robert M. Prisig :-) Available as ISBN 0688052304 and others.
Online you will find stuff on http://www.dns.net/dnsrd/, http://www.vix.com/isc/bind.html; A FAQ, a reference manual (BOG; Bind Operations Guide) as well as papers and protocol definitions and DNS hacks. I have not read most of these, but then I'm not a big-time DNS admin either. Arnt Gulbrandsen on the other hand has read BOG and he's extatic about it :-). The newsgroup comp.protocols.tcp-ip.domains is about DNS. In addition there are a number of RFCs about DNS, the most important are probably these:
Y. Rekhter, R. Moskowitz, D. Karrenberg, G. de Groot, E. Lear, Address Allocation for Private Internets, 02/29/1996.
D. Barr, Common DNS Operational and Configuration Errors, 02/28/1996.
A. Romao, Tools for DNS debugging, 11/03/1994.
C. Farrell, M. Schulze, S. Pleitner, D. Baldoni, DNS Encoding of Geographical Location, 11/01/1994.
R. Ullmann, P. Mockapetris, L. Mamakos, C. Everhart, New DNS RR Definitions, 10/08/1990.
P. Mockapetris, Domain names - implementation and specification, 11/01/1987.
P. Mockapetris, Domain names - concepts and facilities, 11/01/1987.
M. Lottor, Domain administrators operations guide, 11/01/1987.
M. Stahl, Domain administrators guide, 11/01/1987.
C. Partridge, Mail routing and the domain system, 01/01/1986.