You can create as many users and roles as you like and then lock the permissions per role.
You do this via SETUP ->SYSTEM ADMINISTRATION ->USERS ACCESS
Here is a help file to guide you - https://login.shoebooks.com.au/net/pages/Help.aspx?from=users
Tip - if you click on the HELP tab when inside Shoebooks, it will take you to the relevant help file for that page/feature e.g. when you are in Users, click on help and the HELP file for roles and permissions will display.