A little feature that some people don’t know about but would find very very useful: database diagrams in SQL Server. If a picture paints a thousand words, then this feature will help you pick up on the structure of data much more easily.
Within SQL Server, there’s the “Database Diagram” container in each database, in Management Studio.
You can create a new diagram in there, and include all (or some) of your tables, so showing where the relationships are, and what the tables are.
You could also create several different diagrams, each showing a subset of tables and relationships useful to a particular use case.
Jeremy Smyth's blog 