Newbie question: determining best values for use in $TTL and SOA on Bind 8.2.x

[Albert T. Croft]

I have a question (my first to actually post to this
listing), and I cannot seem to find an answer anywhere I
have tried looking. If there is already an answer out there,
however, I would be much appreciative if I could be pointed
towards it.

My question is how can I determine the "best" values to use
for the $TTL line and SOA record for the domains I work
with, or are there such a set of values that are already
highly recommended? I read through the section in the
Cricket book where the RFC recommended values for a root
server were given, and have values similar to the ones in
the Cricket book currently, but was wondering if there is a
way to determine the "best" such values.

Your time and any assistance you may be able to provide are
greatly appreciated.
--
-Albert Croft