There are two ways to mark items in your room as read.
Mark individual items as read
Click the document's actions menu and select "Mark as read"
Mark multiple items as read
Use bulk select to select the items you want to mark as read. Click the "Mark as Read" button at the top of the screen.
You can also select a line item or folder, all contained documents will be automatically selected, and marked as read after clicking the "Mark as Read" button.