SuSolid is an extension for SketchUp that can help you prepare the model for 3D Printing.
It is divided in 4 sections :
1. Solid Check section that shows you all the causes that makes your model a non solid.
2. Solid Repair section that helps you to repair your model and makes it solid.
3. Solid Intersection Check section that shows you all the intersection between solids.
4. Solid Weight section that shows you the weight of the model and every singe component.
On the video you can see how quick you can make this model to be composed by 29 solid entities.
Just try to do it manually and you will see how much time the SuSolid plugin can save you.
You don't need to inspect the mistakes closely, just follow the edge colors and select the appropriate tool for that mistake.
Mostly the best tool selection order is like on the mistakes counter (orange,red,green,yellow).
Next,you can find the intersection mistakes,that can be very expensive if you are designing for production.
And finally you can predict the weight of the product in the designing stage.