With your database open, click on the Office Button in the upper left corner. Click on the Access options button at the bottom of the window. Click on the Current Database Tab.
On the Navigation Section, uncheck the Display Navigation Pane.
On the Ribbon and Toolbar Options, uncheck the Allow Full Menus, uncheck Allow Default Shortcut Menus and uncheck Built-in Toolbars.
On the Applications Options, in the box for Display Form, put the name of the form that you want to open when Access Launches as this will be the only way you can drive the bus.
Your users will see no ribbon menus or navigation panes. They will not be able to change any forms, queries or tables or reports unless you make it available using command buttons and other objects.
As a developer, if you need to access any of the "hidden" objects, you will need to open the database by clicking on the name of the file while holding down the Shift Key. You should not inform your users about this.
Alan