Adding SSO/SAML would be in our enterprise edition. There isn't a plugin for it the current product for it :)
Most of spreadsheet part is self explaining : here are all our demos https://nocodb.com/demos
S3 and Google Auth for newbies can be found here : https://github.com/nocodb/nocodb/tree/master/markdown/plugin...
Having said that, we will be working on the documentation series in coming week.