How To JOIN Two Table and Show to DGV

The best methodology is to write a stored procedure joining the two tables and select the columns you want to display in the UI and bind the data to the DGV.

Other way is to handle the same at the front end as in the below example:
http://www.codeproject.com/Articles/304297/Data-from-Two-Tables-in-a-Single-DataGridView

If you need any help in writing the stored procedure and binding it to the gridview let me know the table names and what are the columns you want to display in the UI.