Here are the facts. First of all it is free. Google offers a basic version free in hopes you will buy the more robust professional version later (for $495). You can buy the pro version if you want, but the free one will do 99% of woodworking stuff. Just go to Google and type SketchUp in the search box. That will take you to the download area and it is painless to get loaded and running. Just open it up and go to work. Once you learn probably four basic tools in the program, you can design most things you will want to do in your shop. If you draw all the joints in detail, it is just like building them in the shop. Plus you can get a really good sense of the scale of any project by adding people, trees, furniture, cabinets and anything else which might be helpful. You can look at your piece from any angle, turn it 360, put it in x-ray mode to see inside (if you drew the joints), add texture and color, and pretty much anything else you may have ever wished you could do when drawing plans on paper. If you are careful with the scale of everything as you draw, you can pull any dimension directly off the drawing. Plus you can take a file of your drawing to a blue print/engineering printer company and they can plot it for you at full scale. When you have that, tape it to the floor and build the project on top of it like lofting a boat.
Sean Headrick writes a very good monthly column in Wood News Online published every month by Highland Woodworking. Follow his detailed instructions to get a good start and get an idea of what this thing can do. Another site I found on the internet is sketchupforwoodworkers which has excellent tutorials for rank beginners. Spend a little time with these tutorials and the ones inside the program and you will be up to speed very quickly.You will not be the first to use this program and many people who use it enjoy posting their finished projects on the internet for other people to use. Go back to that Google search box above and look for the SketchUp Warehouse. You can find a huge number of finished plans there including the one for the clock I built that's pictured at right, which my friend Lorraine drew for me (Yes, that's the SketchUp version she drew pictured at the top of this entry). We only had the hardware and a picture and we scaled everything else from those items. Plus you will see that many magazines and blogs offer SketchUp files you can download for use in building the projects in the articles. You're gonna like this program.