Often times, especially when modeling real world objects, you like to use a reference image to model against. The following video shows how to setup a pair of reference images in Wings 3D. The process is pretty straight forward.
Step 1: With nothing selected, right click and select Image Plane…
Step 2: Select the file to use as your background image.
Step 3: You can now rotate,scale, etc… the image until it is in the location you want. When scaling or translating, make sure you are in body ( B ) mode, so it all scales properly.
Step 4: Now you can add as many more as you want ( side profile, front, etc… )
Step 5: Now you can should lock the image planes so they cannot be selected. Select nothing ( spacebar ), now Select(Menu)->Lock UnSelected Objects.
The following video shows this process, creating and sizing both a front and right side reference image. Of course, there is a Vimeo link as well.