Your Salesforce organization's Sharing Model can greatly impact the visibility of individual records and thus create data skew between different report viewers. This lecture explains the role that the Role Hierarchy plays in data visibility and the impact upon reports.
This lecture shows you how to create and modify dashboards. We also go over the various types of dashboard components that are available, dashboard running users and changing the layout of dashboards.
Resource:
Dynamic Dashboards Cheat Sheet - https://resources.docs.salesforce.com/204/latest/en-...
This lecture covers the creating and sharing settings of folders that house reports and dashboards.
Custom Report Types enable you to report on 3 or 4 related objects. This lecture goes through the example of reporting on accounts with contacts and cases. We then run through cross-filters and grouping in reports.