Ok

Step 1:   Load a "single side square" in Poser.  You find that in  the Props library under "Primatives"

Step 2:   Click on the Materials Room Tab

Step 3:  Make sure you are in "Advanced Mode".  At the top of the working area there are 2 tabs: simple and advanced.  Click the "Advanced"

Step 4:  Also at the top of the window you will see "Object" and "Material". You can pick the prop or character from the drop down menu under "Object", and you can pick the desired material zone for that prop or character under "Material".  Using the "Object" drop down, pick the "Square" prop. It only has one material zone so you don't have to pick a material zone to use.

Step 5:  Right click in the working area and pick "New Node" and then "2D Textures" and then "Image_map"

Step 6:  In the Image_map node, where it says "Image Source", browse to your desired image. Once you have found it, click "ok"

Step 7:  You can click on the "Eye" icon in the upper right of the "image_map" node. That will display the image you selected.

Step 8:  There is a male plug icon in the upper left of the "image_map" node.  You need to plug that into the "Poser Surface Node"  See attached image

Step 9:   Go back to the Pose room by clicking the Pose tab. 

Step 10:   Using your parameter dials rescale the square using the X and Y Scale dials to the dimension of the image. IE:  1024 for X and 768 for Y  or 800 for both X and Y if you image is 800 x 800 pixels

Use the Z Trans dial to move the square forward and backward.   If you push it back you will have to increase the size of the square. use the "Scale" dial for that, not the "XY Scale" dials.

Here is a link to a thread that has bookmarks to material room tutorials and  discussions. I have grouped several beginner tutorials together at the top.  Have a look at those. A couple explain the basics of the material room.

http://www.renderosity.com/mod/forumpro/showthread.php?thread_id=2722867

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi