Mesh/Exporting a mesh from SketchUp
Google SketchUp 8 is a free 3D modeling program available for Windows XP/Vista/7 and Mac OS X 10.5 and later. There is also SketchUp Pro with more features which you can buy, but the free version works for Second Life. It stores model files in it's own .skp format, but it can export models to the Collada 1.4 .dae format that Second Life uses to import models.
Basic workflow
Step 1: Download SketchUp from the Google website and install it on your computer.
Step 2: Start SketchUp 8, and in the Welcome to SketchUp window, click the Choose Template button. Select Simple Template - Meters and then click Start Using SketchUp
Create a box (or monkey or teapot or hippo)
Reduce polygons
Apply textures
Scale to meters
Export to COLLADA
Import to SL
Video tutorial
Importing an Arch <videoflash type="youtube">5KlPvhx_0Ao|640|505</videoflash>
Best practices
Forum thread on SketchUp best practices Another thread on exporting from SketchUp to Second Life