So they asked you to configure dns for microsoft lync and you have no idea how to do this. Well me too, until today. If you have never seen this before, it will throw you for a loop. The protocols are implemented using subdomains, see the _tls and _tcp protocols below.
Example bind9 zone file
@ IN SOA ns1.somehosting.net. hostmaster.somehosting.net. 2012110201 3600 900 1209600 1800
@ IN NS ns1.somehosting.net.
@ IN NS ns2.somehosting.net.
@ IN MX 5 smtp.yourdomain.com.
@ IN TXT MS=ms987654321
@ IN A 216.99.99.99.99
smtp IN A 70.99.99.99
www IN A 216.99.99.99
sip IN CNAME sipdir.online.lync.com.
lyncdiscover IN CNAME webdir.online.lync.com.
_sipfederationtls._tcp IN SRV 1 100 5061 sipfed.online.lync.com.
_sip._tls IN SRV 1 100 443 sipdir.online.lync.com.