I tried Wings3d first, and it's easy to get into and make some compositions of cubes and spheres and whatnot. There's a good starting tutorial
here where you make a simple table.
However, as a programmer, I find it much faster and more intuitive to use OpenSCAD. Instead of clicking on things and moving them around on the screen, you edit code that generates the objects. There are thousands of examples to get you started at
thingiverse. Here's
one of mine.
At the other extreme, Google Sketchup is excellent for the "click and drag objects around" approach. Its UI is way more powerful than Wings3D, and it may even be an easier starting point for non-programmers.