1. Visio

2. Overview From Microsoft's own overview web page:

3. Visio 2003 Overview
Visio 2003 is a diagramming program that can help you create business and technical diagrams that document and organize complex ideas, processes, and systems.
Diagrams created in Visio 2003 enable you to visualize and communicate information clearly, concisely, and effectively in ways that text and numbers cannot.
Visio 2003 also automates data visualization by synchronizing directly with data sources to provide up-to-date diagrams, and it can be customized to meet the needs of your organization.

4. Easily Understand Concepts, Processes, and Relationships
Use Visio to easily create business and technical diagrams to think through, organize, and better understand complex ideas, processes, and systems.
Easily assemble diagrams by dragging predefined Microsoft SmartShapes® symbols.
Use tools designed for specific professional disciplines for business and technical diagramming requirements throughout your organization.
Generate common diagram types from existing data.
Access context-sensitive Help and task-specific templates that are updated regularly from the Web.

5. Communicate Clearly and Effectively
Visualize and communicate ideas, information, and systems.
Create visually rich diagrams for maximum impact on your audience.
Share diagrams in workspace files on your team's Microsoft Windows® SharePoint™ Services site.
Annotate diagrams more naturally using digital ink on the Tablet PC.
Track reviewers' comments and changes to shapes and digital ink using the new review mode.
Publish and share your diagrams with improved Save as Web Page functionality.
Import and export diagrams in Scalable Vector Graphics (SVG) format, a new Extensible Markup Language (XML) standard for Web graphics.

6. Integrate and Automate Systems and Processes
Do more sophisticated work, improve comprehension, and increase productivity to make an impact on your business.
Integrate business processes and systems by extracting data from your Visio diagrams and importing it to Microsoft Office Access 2003, Microsoft Office Excel 2003, Microsoft Office Word 2003, Microsoft SQL Server™, XML, and other formats.
Incorporate Visio 2003 into powerful Microsoft .NET-connected software to address specific business needs.
Embed Visio drawing controls in line-of-business applications built using .NET-connected software or the Microsoft Windows operating system.

7. Visio Help Microsoft Office Visio Help page:

8. Visio Training Tutorials 2003 2010
2010

9. Visio
Where is it?
Woodward 335
Visio 2010