Help with document entry

Technically quite challenged, I find that every time I go to "Documents" and try to add something, I am stuck before I even begin.  "Use the check boxes for the files you would like to upload," it says, but pray tell, where are those check boxes? Darned if I can find them...probably staring me right in the face, I'm sure.  I apologize for this, but I've had to share my documents with you in the Pictures section.  Help requested from a technie to a non-!

(by jim for everyone)