Workflow
Percussion lets you establish role-based workflows to ensure content is reviewed and approved prior to making it to your website.
The Workflow Overview explains how Percussion's workflow works.
Setting up a workflow provides guidance on how to establish your workflow.
Moving Content Through the Workflow is a good primer to show content contributors how they can progress the content through the approval process.
Publishing
Percussion has a variety of publishing options. The Publishing overview describes the publishing job types as well as the publishing output types that are supported. In addition to full site publishing Percussion includes Incremental and On Demand publishing.
Once content is published, Percussion's Social Promotion module provides the ability to post status updates to social networks to bring attention and traffic to your site. Using Social Promotion guides you through the process of configuring and using this functionality.
Security
Security works hand in hand with workflow.
Managing users explains how to bring users into the system, both manually, and using LDAP.
Managing roles shows you how to establish roles in the system and what those roles can do.
In addition to workflow, Percussion also supports Folder security to provide additional flexibility for limiting which users can access which content in the system.