If you are using the query designer you'd look on the main process object and then the collection and then select the attributes from the particular collection. So Incident/Notes and then Title or whatever. You can also write your query against the collection directly by starting your query against Incident Notes and then refer to the incident attriubutes if needed.
If you are using Crystal, then I'd take a look at the standard Incident.RPT file delivered as that shows you how to refer to and report on collections using subreports.