CiviCRM has an extensive user guide that has helped tens of thousands of people learn to use the system more effectively. So does Drupal.
Over the last few years, we've been adding easy-to-follow tutorial videos for Drupal, CiviCRM and Wordpress covering some of the common workflows that affect our clients. You can view the ones we've released on our YouTube channel and more are available for our clients.
If there's something you'd particularly like to see there, get in touch. We have further guides and resources available on our client portal.