The Beginner Theme is the "Hello World" of theming. If you've never tried to write a theme before, and are somewhat unclear about what that even means, you can start here. The code is extremely short, extensively commented, and meant to be understood by somebody who has never looked at a theme before. Dive right in!
This module works in conjunction with the amazons3 module to provide direct to S3 uploading from your browser. Bypassing the Drupal file system and storing all files in S3 only.
When using this method to upload files to S3 files are uploaded directly from the user's browser to S3 and not stored in the local file system. This can be nice in that you don't have to upload files to Drupal first and then have Drupal transfer them to S3 for you. The module then stores a managed file record in Drupal for the new file and the file is then treated just like any file that was uploaded via the normal means.
The module provides a new field widget for file fields.
The module provides a new #type = amazons3_cors_upload element that can be used by others and functions similar to the #type = managed_file element. Display a file upload widget and when the form is submitted your submit handler will be given the FID of the new file.
Both the field widget and FAPI element support display of upload progress via XHR upload progress in browser's that support cool things like that.