to get the hang of SQL, you can build a query that performs the action you want to perform...then click View/SQL View. This will give you the syntax in SQL. You can copy and paste this into your record source of your form.
Alternatively, when you are in design mode of your form, in the Record Source property, select the query builder. This will bring you to a design grid where you can place the fields you want. Then, instead of saving, just exit the grid...Access will ask you if you want to save the changes to the SQL statement. Say "yes" and the appropriate syntax will show up in your record source.
Good luck!