You can also browse through the lessons from the following Inventor 2009 courses and watch sample lessons from each course.
Inventor 2009: Solid Modeling
Inventor 2009: Assemblies and Advanced Concepts
Inventor 2009: 2D Drafting and Customization
Inventor 2009: Sheet Metal Design

Sheet Metal Design Lessons
(Sample lessons comming soon.)
Introduction
The Sheet Metal Environment
Styles and Templates
K-Factors
Creating Bend Tables
Using Bend Tables
The Flange Command
Bend Reliefs and Remnants
Bend and Sheet Metal Styles
Unfold Methods
Corner Seams
Bend Transitions and Flat Patterns
Custom Sheet Metal Templates
The Contour Flange Command
Looped Contour Flanges
Shells and Ripped Seams
Editing Flat Patterns
Using the Hem Command
Multiple Plates in Assemblies
Extended Surfaces
Using the Punch Tool
Custom Punches
Flat Pattern Punch Representations
Custom Extruded Louver Punch
Dangling Geometry in Punches
Custom Extruded Dimple Punch
Custom Revolved Dimple Punch
Surfaces
Tabs
Double Bends and Bend Allowances
Knockouts
Flat Patterns on Drawings
Export-Import Flat Patterns
From Flat Pattern to Folded Model
Custom Sweep Punches
Rules for Complex Shapes
Lofting Conical Shapes
Sweeping Conical Shapes
Complex Shapes
More Complex Shapes
Frame Generator
Editing Frames
Preparations and Welds Part I
Preparations and Welds Part II
Post Weld Operations
Conclusion