Here is how you can add instructions to users for cell entry information:
It’s easy to add instructions to help your users enter data into any cell in Excel. This can be done quite simply using Data Validation.
Select the cell where you want the data entered. Then go to Data Validation on the Data menu of the ribbon. Choose the Input Message tab on the dialog box:
Enter a title for your message and what you want the message to read. Make sure the box is checked for “Show input message when cell is selected”:
Now, when you click on that cell, the message will appear:
Piece of cake!