You need an "A" or "CNAME" record for any name you wish to be publically resolvable to. Also, in order to be the DNS provider for your domain, you need to setup a nameserver record that point to your DNS server. Ultimately, you'll need at least 1 A record which has your IP in it... and as many CNAME records to point to any sub-domains that point back to your A record.
if you have abcd.com you'll need a minimum of 3 records at the root to make "abcd.com" resolveable.
- SoA record - this record says you are the "Start of Authority" for this domain.
- NS record - this record says what server is used to resolve names for this domain
- A record - this is the actual record used to associate a name with an IP.
From there you can have sub-domain records as you see fit.
Online tools like "nwtools.com" can be useful to figure out what DNS records can be resolved. It would also be useful to know what sort of DNS server you are running (Bind 9? Microsoft DNS? etc..)