The first step when editing items in a LEO unit is nearly always to turn editing on. Click on the 'Turn editing on' button in the banner, or the 'Turn editing on' link in the Administration > Unit administration menu.
When editing is turned on, you will see a long list of all the sections in the unit and all the activities and resources in each section, as well as a number of editing links and icons.
At the end of every section there will be an 'Add an activity or resource' link. Click this link to bring up a popup box which lists all the possible activities and resources that can be added to a unit.
Each activity and resource is described in the Tools section of the LEO Guides.