1. From your Dashboard, select "Item" in the left sidebar menu, then click the green "Add an Item" button.
2. From the "Add an Item" screen, you can fill in your Dublin Core metadata for the item. Note that you can tab over to "Files" to add the file for your item.
3. In the "Files" tab, simply click "Choose file" to browse your computer and locate the item you'd like to add.