To start editing your first document, spreadsheet or presentation, first create a new file by tapping the (+) button at the top right of the screen. You will be prompted to create a new document, spreadsheet or presentation.
Choose the appropriate document type. You will then be asked to enter a name for the new document or spreadsheet. 
You don't need to add a file extension. Office2 will do this for you automatically. Press OK to create the new document or spreadsheet and start editing.
The user guide is a useful source of information and describes in some detail the full functionality of Office² HD. You can access the user guide by pressing the help button in the toolbar.
When you are finished browsing this page and you wish to go back to Office² HD, press the Done button in the top right corner of this window.