How to Create a Custom Report Type
Custom report types are used when a report type you need does not yet exist OR when you create custom objects and need report types for your new objects.
Choose your Primary Object. This is going to be the controlling object in the report. All other objects that you want to include in this report will need to be related to your Primary Object. Also, give the report type a Label. This should be descriptive and include the objects in the report so that you can reference it later. Also provide a Description, choose a Category in which to store the report, and select Deployed if you are ready to use this report type in your production.
You are finished! Now, follow these instructions to create a new report and select the report type you just created: