Making Textures on One Side Only of a Flat Object

After rezing a flat square board I have forgotten how to apply a texture to one side only of that flat square board. I recall it has to do with "Select texture" and "Edit Linked Parts" in the Texture Tab in Edit, but I cannot remember the exact things to do to to end up with the texture on only one side of the board. Whenever I try various combinations of choices I end up with the "Circle and crosshair" of the "select texture" on both sides of the board. What am I forgetting to do correctly?
Thanks,
BJ

It's just a single flat prim? OK, open the Edit window for the prim, then choose the Textures tab. Click the Select Texture radio button and click the face you want to texture. Use the texture picker window to select the texture you want. Bingo. That's it.

Or, easier ..... Open your inventory. Find the texture you want, and then drag & drop it on the face where you want it. Bingo again (only faster).

Actually, either of these methods will work on a multi-prim object just as well as on a single prim.