Click on Content Buckets
Click on Create Content Bucket
Give your new bucket a name and description.
From here you can upload your content via individual uploads or via a zip file upload.
To upload files in bulk, you will use the Zip File Option.
You will start by saving your graphics as png files and putting them into a folder on your desktop.
Then you will use the Simple CSV Sheet to add your file name, caption and first comment (for Facebook only).
Add that CSV Sheet to your Folder with your Graphics
Compress or Zip that folder.
Click on the zip icon in the Content Bucket and upload that zipped file.