The configuration of the DMZ in the device can be broadly divided into these three parts:
Interface Security Level -- Traffic is allowed from a higher security interface to a lower security interface by default. But, the reverse case is blocked
Translation Rules -- Translation rules can be dynamic nat, global, or static.
Traffic Permission Rules -- Traffic Permission rules are access-list and access-group rules applied in the configuration of the firewall to permit the traffic to go through the interface.
For DMZ configuration use this document it contains examples.
http://www.cisco.com/en/US/docs/security/asa/asa72/getting_started/asa5550/quick/guide/dmz_n.html