What should DNS entries look like?

All my sites are down - need to understand best practices (quick)

[intellivision]

I have a virtual private server, and after a reboot early this morning, all sites are down with "Server not found" messages. Pinging the domains confirms this. The server is up - I can ping the numerical IP and log into the Plesk control panel.

Why/how the DNS got so messed up is subject to another post in another time, but I did have a Linux guy look at my server a couple months ago and he mentioned that DNS was a house of cards.

So now the house has come down.

I have 12 domains on it, and one of them is the "master DNS" -- sorry, I don't know the correct terminology. Here is the "master DNS domain" configuration:

192.168.0.1 / 24 PTR example1.com.
example1.com. NS ns1.example1.com.
example1.com. NS ns2.example1.com.
example1.com. A 192.168.0.1
example1.com. MX (10) mail.example1.com.
ftp.example1.com. CNAME example1.com.
mail.example1.com. A 192.168.0.1
ns.example1.com. A 192.168.0.1
ns1.example1.com. A 192.168.0.1
ns2.example1.com. A 192.168.0.2
webmail.example1.com. A 192.168.0.1

And here is a sample of one of the other 11 domains:

192.168.0.1 / 24 PTR example2.com.
example2.com. NS ns.example2.com.
example2.com. A 192.168.0.1
example2.com. MX (10) mail.example2.com.
ftp.example2.com. CNAME example2.com.
images.example2.com. A 192.168.0.1
mail.example2.com. A 192.168.0.1
ns.example2.com. A 192.168.0.1
webmail.example2.com. A 192.168.0.1
www.example2.com. CNAME example2.com.

So my question is this: do those look right? Anything jumping out?