First of all, many thanks to the folks at AtLast Software and at Google for making SketchUp Pro available to educators at such an unbelievable price — it’s now free for instructors!
As I re-acquaint myself with the application and begin to gear up for making illustrations of the crawfish boats, I am finding that there is an amazing variety of educational materials. One is Google’s own collection of videos, which are divided into sections for new users, intermediate users, advanced users, et cetera. There’s even a video on modeling a tractor.
There is also something called The SketchUp Show, which has a variety of lessons — they are up to Show 56 at this writing.
There is also a SketchUp Cookbook published O’Reilly — link is to Amazon. If you have O’Reilly’s Safari Online Book service, then you can find the cookbook here.