• SketchUp For Educators Frequently Asked Questions (FAQ)
• Google Educator's Sketchup page: Has lesson plans and a quickstart guide, and incorporates SketchUp with Google Earth & unitedstreaming.
• Student Gallery: Look at what these students are making!
• Case Studies: Check out these detailed examples of how specific schools are using and integrating sketchup.
• The SketchUp Student Workbook: a perfect book for your classroom. The initial chapters provide all basic concepts, which students then apply and build upon while working on "do-it-yourself" projects. Minimal guidance is provided when necessary. The accompanying Instructor Guide contains all necessary steps for each exercise and project, as well as cross-references to pages in the Workbook.
• List of K12 schools using SketchUp Pro: So who else is using this program? See a long list of schools using it!

How do I start using SketchUp?

• SketchUp Online Video Tutorials: Amazing step-by-step tutorials that walk you through specific SketchUp skills to perfect your SketchUp Fu.
  
• Official SketchUp User's Guide - Online: Hyperlinked & searchable. 'Nuff said.
  
• Official SketchUp User's Guide (PDF): Want the guide on the go? Grab it in PDF format.
  
• Quick Reference Card (PDF): A handy, 1-page card that explains what all those menu buttons do.

What are other people doing with it?

• SketchUp Examples: See a small sample of what people are making
• 3D Warehouse: A massive collection of SketchUp models, made by users like you!

I need more specific help. Where do I go?

• SketchUp Frequently Asked Questions (FAQ): browse often-asked questions by topic.
  
• Sketchup Help Group: A link to a Google Group of Sketchup enthusiasts. Join and receive assistance from others that are using this wonderful program!

• SketchUp Components: Components are pre-drawn objects (like trees, cars and people) that are useful for creating reusable models to be placed within other models. Google has included dozens of components in Google SketchUp (free) to help get you started, but there's lots more available. Here are some additional libraries of components that will help you create more advanced SketchUp models.