Modeling and working with data on the Dataverse within the Power Platform

The Common Data Model - Is an industry agreed approach to storing commonly used data.  Use it to store applications across your company/organisation.  Results in a single source of truth instead of multiple copies with data contained in different schema's.

Two types of relationships namely: 1:N and N:N (Dataverse hides the associate entity/intersect entity that is created in the background).  

Use "Option Sets" for small static data and use "Lookups" for larger or changing data.  In Multiselect Option sets for N:N relationships, rather use "Lookups".

SSMS can be used to view data using T-SQL, better to use "SQL 4 CDS" as it provides a full ability to work with data within the XrmToolBox.

XrmToolBox - is a 3rd party download that has a ton of contributed tools and there are good options for modelling data.

Excel and browser plugins - Can be used to import/export data and there are some nice Edge/Browser plugins to help such as "Level up for Dynamics 365/Power Apps"

The built in browser Dataverse management tool is super easy to use to model your Common Data Model further.