Where do I sign up for S3 Amazon?
You can sign up to the Amazon S3 AWS here: https://aws.amazon.com/getting-started/
If you have already a general Amazon account, you can use that account to activate the S3 service by logging into your account and then on the far right, click on Web Services Account. See screen shot below (may vary slightly in time):
Then just follow the instructions. You do not need to prepare anything upfront and you are not charged a setup fee, but they will ask for your credit card details.