note: This is a rough draft, feel free to change, add on to, or correct spelling and grammar. -arquebus
Wings is probably the only 3D application (besides Nendo that was big inspiration for Wings developers) where you can learn just by using it, because the tools are accessed by right click menus rather than being spread out in toolbars. Only the tools you are currently able to use will be in the right click menu, depending on what selection mode your in. Wings is a box modeling application, which means polygonal modeling that grows out from a primitive object (usually a cube, hence box modeling) where you use four basic actions: move, extrude, scale and rotate. The geometry you create from these actions can be further refined by things like beveling, cutting edges, etc. Wings also has a smoothing function more popularly known as subdividing or sub-d. This not only gives you more geometry by dividing faces in half, but also smooths the shape of your model by rounding corners depending on closeness of edges.
Second Life edit
Wings can be used to make sculpties (also known as "sculpted primitives") in Second Life. Currently, the best information is in the Second Life forums. If it becomes wider used, information specific to Second Life should be developed here.