To put some content here, go to Site Admin -> Appearance/Presentation -> Widgets -> Select "Left Sidebar" -> Click "Show" -> Click on "Add" on one of the widgets on the left side -> Click "Save changes" -> Done

WordPress Step by Step Tutorial Step 17– Adding Navigation Widgets to the Sidebar.

Now that I have had the site up for over a month, it’s time I think to add some content to the sidebar.   As it stands right now, we are not providing users with any way to access older content other then searching for it.
To do this we are going to add some additional widgets [...]