Thank you for posting your question about Access queries here! Specifically, you asked:
How can I create a query tell me what records may be in one table (the many side) that does not have related data in the other?
The cool thing about Access is that it makes building this kind of query really easy using the Query Wizard. I'm not sure what version of Access you are using, but in Access 2010, you can:
1. Open your database in Access 2010 and go to the "Create" Ribbon.
2. On the "Create" Ribbon, click on the "Query Wizard" button. This will start the Query Wizard.
3. On the first page of the Query Wizard, choose the "Find Unmatched Query Wizard" option (which is the 4th option), and click OK.
4. This will launch the "Find Unmatched Query Wizard". Follow the on screen steps in the wizard to build the query (for your specific database tables) and the query will be created!
Anyway, I hope that helps, but if you have any more questions, please feel free to respond and I will do my best to help!