Create a locked down Linux Mint Desktop

I need help in creating a locked down desktop installation of Linux Mint to use as with an openbravo based point of sale software. User of this desktop should only have access to the point of sale application and no access to any other program or modify system settings in any way, basically a kiosk computer. Approach to this project could be either by providing me with instructions on how to modify the system or could be a personalized distribution of Linux Mint, or could be creating a Linux program that allows me access to different options in restricting the desktop.