CutList takes the current Sketchup selection and produces a list of the parts, their sizes and quantity of each. The plugin also can produce a layout of the parts on your selected material size and can be useful for estimating materials for constructing your model.
The default settings are designed so you can install and get useful output with just 3 clicks!
The material list can be produced as a text file or a browser window display, which can also be printed. A material list can also be produced as a CutListPlus(CLP)* import file which has more sophisticated material layout and costing functions than built in to the plugin.
The layout can be produced in a browser window display(standard setting) or an svg file both of which can also be printed. Svg files can now be opened by most browsers.
Runs on both Mac and Windows. (Note: layout for Mac can only be produced as an svg file due to Safari browswer security restrictions).
Works for both metric and imperial measures.
Though initially geared towards woodworking, it has also been used for metalworking, plastic, etc.
Additional instructions, FAQs, tutorials, features and guidance is available at https://code.google.com/p/cutlist/
*CutListPlus is not my work but is a nice pay program by Todd Peterson for professional results. Most people won't need the advanced features but if you do, it's the next step up from CutList.