Help to make a new DNS server

[Yena]

Hi, i would like to setup a DNS Server.
Please, i need some help to check mi step:

1) I have registered my domain:
    example.cxm

2) I have installed Bind 9.2.1 on a RedHat 9 Server.
I have created my zone file in /var/named/pz:
-------------------------------------------------------------
$TTL 60
@               IN      SOA     ns1.example.cxm. info.example.cxm. (
                                2001122007;
                                6H;
                                2H;
                                1W;
                                1H );
                        NS      ns1.example.cxm.
                        NS      ns2.example.cxm.
                        MX      5       mail.example.cxm.

localhost               A       127.0.0.1
example.cxm.        A       xxx.xxx.xxx.xxx
mail                      A       xxx.xxx.xxx.xxx
www                    A       xxx.xxx.xxx.xxx
ns1                      A       xxx.xxx.xxx.xxx
ns2                      A       xxx.xxx.xxx.yyy
-------------------------------------------------------------

and i have add in named.conf:
zone "example.cxm" { type master; file "pz/example.cxm"; };

3) I have add in my registrant pannel the 2 new DNS:
    ns1.example.cxm
    ns2.example.cxm

Is it all correct? Have i to set or do something else?
Have i to set also the PTR record?

Thanks a lot

                                    -- Yena --