OK, I know not everyone is a CAD engineer, but Google SketchUp is a great tool to mock things up. It takes some time to learn, but can be fun and let you get a chance to see it before you put saw to wood.
I made a model of my tank stand before putting it all together. It is desinged for as many simple cuts as possible since I am limited to power hand tools. I wish I didn't live halfway across the country next to my Dad since he has an awesome woodworking shop with table saws, power mitre/chop saw, band saw, planer, jointer, drill press and more that would have made this project come out much better!
So far I am pleased with it. Some minor imperfections but mostly ones that I only see that drive me nuts! Painted in black to help hide some things
Here is the link on Google 3D Warehouse.
PS - If you don't want to install SketchUp, you can view the model through Google Earth and the
3D Warehouse Network Link.