Bearing in mind that EC2 local storage is not persistent, and that in case of hardware failure, you will lose all data stored in your instance, understanding AWS's persistent disk service, the Elastic Block Store is especially important. This short course will introduce you to provisioning EBS volumes, and using them for enhanced reliability as EC2-attached data and backup snapshots.
Note: some elements of this course are a bit dated. You might like to view the "Storage" video from the AWS Storage Fundamentals - AWS 140 course for an updated version.