This took a bit. On the first site it was easy. I went through these directions to get ckeditor setup with paperclip.
And paperclip is easy to setup with S3 but on this site you are reading now the url Amazon used was not but 

Paperclip was defaulting to s3 and I had trouble getting the combinations for this setting right. Maybe I could have set the bucket to use s3 but in the end I rather deal with the s3-us-west-2 since different clients will have different needs.

Finally I setup the development.rb and production.rb like this

You can see the URL below of the image and the PDF

And a PDF