When you create fields for your tables you must decide whether they are required, whether they have a default value and whether they can contain NULL values. Learn to make the right choices with this tutorial.
Learn what the Required and Allow Zero Length properties in Access are and how they are different from each other.
Learn how to create Access validation rules with this Access validation rule tutorial.
Learn how to create a many-to-many relationship in Access.
Learn how to create a one-to-many relationship in Access 2010.
Learn how to use input masks to constrain the input of text fields in in Access 2010.