This video shows how to use Eagle PCB to create a custom library and components.

Part 1 (schematic):    • Eagle PCB Tutorial: Schematic  
Part 2 (layout):    • Eagle PCB Tutorial: Layout  
Part 3 (finalizing design):    • Eagle PCB Tutorial: Finalizing Design  

Table of contents below:
00:00 Introduction
00:37 Checking other libraries
01:54 Opening a library
02:33 Creating a new library
03:09 Creating a new package
18:08 Creating a new symbol
23:19 Creating a new device
26:11 Using the new library
28:00 Conclusion