After adding a node to be monitored and you select "List Resources", you are able to select the items to be monitored.
How can I find the OID #s that were found?
There are several KB articles around which OIDs Orion polls depending on the resource. Check out this KB for interfaces and there should be related KBs listed for other Orion resources.
SolarWinds Knowledge Base :: What object IDs (OIDs) does Orion NPM poll for interface information? What types of interface information does Orion NPM poll?
Retrieving data ...