Simply click '+ Add items' and select the user (for multi user and partner accounts only).
Then 'Click here to select files' its that easy!
You can upload more than one item at a time - just remember to make sure you are uploading items as one of our supported file types (PG, PNG, GIF, BMP, TIFF, PDF, .zip files with images, DOC, DOCX, ODT, and RTF).
And with the new 'Drag and Drop' feature it is even faster!
If you want to upload a PDF with more than one item make sure you select 'Multiple item PDF's' option*: