If you're just starting out with OpenAudit I'd recommend starting with the
Open Audit version 2 betas. OAv1 is old and no longer maintained.
With that out of the way. To audit with Open Audit v1 you need the audit.vbs script and a properly configured audit.config file. Depending on the audit.config file the audit.vbs will audit an individual machine or the domain. Post your audit.config file with any private information (passwords, domains, etc) removed and we can review.
If you want to audit an entire domain and you have relatively fast network links between all machines it's easiest to have a single machine run the audit.vbs which then queries all machines in the domain and posts the responses to the OA database. I think most of this is covered in the
FAQ forum.