The SharePoint Security Model

SharePoint "Users" (also known as Security Principals) may be either Active Directory users or Active Directory groups.  These "Users" are contained in SharePoint "Groups."  SharePoint Groups are mapped to a permission level for a "Securable Object."  The mapping of groups to permission levels occurs at various "Scopes".  Although any site, subsite, list, library, folder or item is a securable object, not every object creates a scope.

List of SharePoint 2010 Training Videos

Following is a list of SharePoint 2010 videos from simple to complex...

Introduction to SharePoint

Videos, microsoft sharepoint:
Very high-end, introductory.

Learning Snacks, microsoft learning:
Introductory, What's new.

E-Learning Clinics, microsoft learning:
Free two-hour clinics, one for Developers, one for IT Pros.