To add new users to IsleBooks POS, here's what you need to do:

1. Head to User Management -> Users -> Add New.

2. Fill in the user's info, like their name, email, and other details.

3. Pick a role for the user from the list of available roles.

4. Come up with a unique username for them.

5. If the commission agent feature is turned on, you can set the Sales Commission Percentage (%) for this user.

(Note: This might not be available in IsleBooks POS-LITE.)

6. Decide if the user should be active or deactivated by checking the "Is active?" option.

7. Click "Add" to make the new user.

You can also change or delete a user by going to the User Management area and selecting the user you want. You'll see options to modify their details or remove them from the system.