Okay so,
I download models from the 3D warehouse… Where do they all go?
How do I organize or do downloading correctly to make my work go faster?
How did you download it? /from your browser or from inside sketchup? Downloads from the internet usually go into the Downloads folder on Mac. But you may get a dialog that asks you where you want to put it. In that case look at the location next time.
In SketchUp it is downloaded into your model. So saving the model saves what you downloaded. It is a good idea to open a new document (other than the one you are modeling in), download the 3D Warehouse model and save the sketchUp file into a special folder for SketchUp model downloads, that you have in a handy place. From there you can organize your models according to content, depending on your usage. For architectural, you can have separate folders for furniture, appliances, people, plants etc.
One thing to watch for. New downloads of SketchUp create a folder called SketchUp Files. When saving a model the save dialog might default to that folder. You only have to be aware of what folder is showing when you save, and change it if you want another folder. You can also change the default model folder in “Preferences / Files”
Whether saving the SketchUp model. or moving models from the Downloads folder, the result is the same, put the models in a folder for downloaded models or components, or subfolders of types of models.