Hi, firstly, you will need to create a Primary Master zone for your internal network, such as mydomain.home. (remember the trailing '.'), this will by default create an ns record with a ptr record for 10.0.0.1.
If you are happy with the ns record for the server, leave it there, but select it and modify it's IP address to that of your server.
Next up, you then simply need to add additional Machines (A records) for each additional computer you wish to use and make sure your other computers are all running on static internal IP addresses.
You can verify your new A records by looking in the reverse lookup, ie, if your server IP is 192.168.1.254, you would look in the link 1.168.192.in-addr.arpa. which should give you a list of all IP's being used under that IP range and what names they attach to.
Finally, after a quick reboot, do a few checks to make sure everything is good to go:
open terminal (/Applications/Utilities) and type the following:
host 192.168.1.254 <return> (replace with your server IP)
host ns.mydomain.home <return> replace with the full domain assigned to your server
sudo changeip -checkhostname <return> (enter your admin password)
You should get results similar to:
254.1.168.192.in-addr.arpa domain name pointer ns.mydomain.home
---
ns.mydomain.home has address 192.168.1.254
---
Primary address = 192.168.1.254
Current HostName = ns.mydomain.home
DNS HostName = ns.mydomain.home
The names match. There is nothing to change.
If all is good, just set the DNS of your client machines to that of your new server and you're good to go.