These are some random tips that I learned while teaching myself Google SketchUp. Please add others you have learned along the way, too!
When using the Orbit tool, if it isn't doing what you expect it to do, try holding down the Control (Ctrl) key while you orbit!
As you design, if you want to create steps separately, you can add a new layer (Windows > Layers (to make the Layers palette visible) > click the + sign > type in name (i.e., "Step 1") and ensure that this layer is highlighted to ensure that everything you want on this layer can be turned on or off with one click by checking or unchecking the Visible option to the right of the layer name). I add a new layer for each step so that I can turn them off and on as I need them (like for making print screens/screen shots for building instructions)!
I also add a layer and name it dimensions (using the same steps mentioned above). On this layer, I create dimensions for my project using the Dimension tool and also turn the layer off and on as needed!
Materials (Custom Collection)
You can make your own custom materials collection, if you have .jpg images for which you want to use. Make sure your patterns are "seamless" for best results (i.e., the pattern edges don't appear to have a seam when it is applied)! To add custom materials, Windows > Materials (to make the Materials palette visible) > select the details button just to the right of the materials name box - it has a paper with a right-pointing arrow under it > select Open or create a collection... > browse to your stored images on your computer - these should be stored in a folder of their own somewhere > click OK and your custom materials collection (all the suitable .jpg images stored within that folder) should appear as an option in your materials list now!
Also remember...Undo (Ctrl+Z) is your friend! =)