Absolutely! If it's registered here, you're halfway to getting it going. The other half is to go to the DreamHost panel where you manage your plan and currently hosted domain. Click on Manage Domains, and at the top of the new screen, Add New Domain. Be sure to the pick Fully Hosted section if you want to manage/upload your own content.
You may host an unlimited number of domains, users, mailboxes, databases, etc. here.