determine the right SOA values in ddns

[Hannah O Day]

All,

I need some help on determining the SOA values and $ttl value.  My dhcp
lease time is 10 hours.  I need to make sure the zone transfer is frequent
enough that users will not notice any delays (especially those applications
that depending on the hostname for authentication).  All my users are
pointing to the slaves for queries.  What values would be  fast enough but
won't be over kill ?  (ttl, refresh, retry, expire, and neg cache?)  I'm
running Bind8.2.3.

Thanks!

Hannah Day