UV Mapping multi faces basics

I’m really struggling with mapping a single face. Arrggh. I’m using 2.48a and what I want is a particular picture mapped onto one side of a cube whilst maintaining the material colours (not pressing texface) on the other sides. What I’m doing at the moment is…
a) i have my default cube.
b) Go into edit mode(face select), highlight one face, press ‘u’ and unwrap.
c) Now I see a new UVTex if I press F9 so I know that i’ve createed a new UV texture - right?
d) I create a new texture under the object material.
e) I click on ‘map input’ for that texture and then click UV and put in the name of the uv texture i previously created.

At this point I think Im done but when I render the picture is applied to the obejct in a more or less random way and not that particular face that I unwrapped. What am I missing?

Can someone give me a quick step by step procedure - driving me nuts.

In fact, for maping texture image to face of so simple mesh like cube , there is no need UV unwrap.
Instead, in edit mode select all faces and under “Links and Materials” tab create New material (e.g.mat1) then Assign and set color for entire object. Select face you want to assign texture image, create New material (e.g.mat2) > Assign. Now your cube has two materials - mat1 for object color mat2 for maping texture to face. Go to shading buttons (F9) choose mat2 under “Links and pipeline” tab and add your texture. Leave texture maping as is (Orco and Flat).

Thanks Jawra - that cleared up a couple of things for me. I simplified my original question a little from what I actually want to do - for sake of posting. I’m trying to apply a ‘branding’ print to the side of a car tyre and I don’t want to use the ‘decal’ method. I used the method I mentioned above to unwrap the side of the tyre and apply the texture but to no avail. Any ideas?

To do what you want without UV unwrap just create material for all faces , then select faces you want to put image on and click ‘New’ on ‘Links and Materials’ tab and then ‘Assign’.

Click on image to view larger .PNG ~225kB.

Now add texture with settings as below.

Click on image to view larger .PNG ~350kB.

However , UV mapping gives more control over displaying/mapping texture and if you prefer that for some reason , you may do so by creating ‘shading domain’ ( New material ID ) for texture like on first image then go to side view, A key or 2xA key to select all faces, shift-S key>Cursor to selection, C key for centering cursor/object in viewport, U key to enter ‘UV calc’ menu and choose ‘Project from view’ or ‘cube projection’. Select UV input instead of Orco.

Click on image to view larger .PNG ~360kB.

And zipped .blend FILE with UV and Orco solution - just switch map input UV/Orco.

Another tip : if your texture doesn’t map corectly try to play with small buttons X/Y/Z under Map Input tab. They are for switching mapping axes.
You can find more info on Blender wiki page.