DNS for Private Network

[Todd Beauchemin]

I have setup bind on my linux system to handle dns requests for
my network rather then using my ISPs DNS.  What I would like
to do is create my own private domain adding in the servers on
my local network.

I use the following for IP addresses 192.168.1.1-255.

So far I have tried the following for the zone and in-arpa-addr
files:

$TTL 86400
@ IN SOA dns.todds-world. {
   1999090200 ; serial no
   360000  ; refresh
   3600  ; retry
   360000  ; expire
   3600  ; default ttl
  }

; Name Servers
 IN NS dns
gateway   IN A 192.168.1.1
tw-ap01   IN A 192.168.1.7
cerberus  IN A 192.168.1.56
dns   IN CNAME cerberus
tdsmail   IN A 192.168.1.60
gutenberg  IN A 192.168.1.98

and

$TTL 86400
@ IN SOA dns.todds-world. {
   1999090200 ; serial no
   360000  ; refresh
   3600  ; retry
   360000  ; expire
   3600  ; default ttl
  }

1 IN PTR gateway.todds-world.
7 IN PTR tw-ap01.todds-world.
56 IN PTR cerberus.todds-world.
60 IN PTR tdsmail.todds-world.
98 IN PTR gutenberg.todds-world.

However bind keeps give me parsing errors.  What am I doing wrong?
Is this something that I cannot do?

-- 
~Todd