This is found in both tools on top toolbar, and its the green blue and brown icon on the left hand side of screen. Before you click it, click edit and clear selection.

Now click on browse and have a fumble about for a texture, dont spend hours just choose one! now, at the bottom on this texture applicator is grey button, saying mode: lift and select etc, its pretty self explanatory, but for those of you who are lazy:

lift and select: lift the current texture and values on an object and select it

lift: lift the values and texture of a current object

select: dunno!! :P

apply texture: what could it be!! :P

apply texture and values: apply the texture and the values you have selected,

At the top of the screen you will see scale and shift, I suggest you click an object with a texture on using the lift and select mode, and press hide mask, then try upping and lowering the x and y values, you will see the textures moving about.

Theres also various other options such as fit, r, l, if you select your object by clicking "lift and select" you can then press the fit button and the texture will fit into your object. There is also "world" and "face" to choose from, tick world to align with the other textures next to it, its hard to explain really, your best playing around with it to see.

Recapping. To apply a texture to one face, clear your selected object, in other words have nothing selected in wc. Then turn on texture application, choose your texture by browsing, then in the drop down box select "apply texture" or "apply texture with values" and then in camera click on the face you want to change. Your best bet is to try out all the features for yourself and see what you can do.