Yes, this thread is effectively dead, but dragonfx's answer was tantalizingly close yet too vague for ubernewbs such as myself. I added this post to help future frustrated users.

This thread explains in a little more detail what's going on, and provides a bit more insight into Maya. After reading both threads I solved the problem by starting with a model and opening the Channel Box, and then watching what changed when I did a planar projection. There appeared a new input called polyPlanarProj1, and when I selected that the manipulators appeared. So, hours after following the simple tutorial steps and scouring the manual and the web for info on how I can use the program, I can now proceed with the mapping. :angry: