Configuring Bind for serving as nameserver for multiple domains

I have installed bind9 on a Debian VPS, and use it as nameserver for one of my domains. It works well. dig reports correct entries.

I now wish to use this nameserver for four more domains, and am a bit confused about certain configuration parameters.

The primary domain I used is drjoel.in, for which I have set up the following in master zone file

cat /etc/bind/named.conf.local
zone "drjoel.in" {
     type master;
     file "/var/lib/bind/db.drjoel.in";
     allow-update { key rndc-key; };
};
zone "31.167.199.in-addr.arpa" {
     type master;
     file "/etc/bind/zones/rev.14.31.167.199.in-addr.arpa";
};

I have added this:

zone "relsoft.in" {
     type master;
     file "/var/lib/bind/db.relsoft.in";
     allow-update { key rndc-key; };
};

for my second domain, and the following in /var/lib/bind/db.relsoft.in:

relsoft.in.       IN      SOA     ns1.joel.co.in. admin.relsoft.in. (
                   2007010401           ; Serial
                         3600           ; Refresh [1h]
                          600           ; Retry   [10m]
                        86400           ; Expire  [1d]
                          600 )         ; Negative Cache TTL [1h]
;
relsoft.in.     IN      NS      ns1.joel.co.in.
relsoft.in.      IN      NS      ns2.joel.co.in.
relsoft.in.      IN      MX      10 aspmx.l.google.com. 
relsoft.in.     IN      A       198.23.228.223
www.            IN      A       198.23.228.223
ns1.            IN      A       199.167.31.14
ns2.            IN      A       38.114.103.106
mail.relsoft.in.        3600    IN      CNAME   ghs.google.com
*.relsoft.in.   3600    IN      CNAME   relsoft.in.

My /etc/resolv.conf currently looks like this:

#cat /etc/resolv.conf
search drjoel.in
nameserver 199.167.31.14

My questions are:

1. What should my resolv.conf be, to allow me to use this server as nameserver for both domains?
2. Am I correct in assuming that I shouldnt add a reverse DNS (PTR) for the second domain, since I already have one for the first domain?
3. Other than editing /etc/bind/named.conf.local and adding /var/lib/bind/db.relsoft.in, are there any additional steps to do?