Let's take a wood texture (mo matter where it's from), click on the second sphere, double click at diffuse color on Bitmap:
There we choose our wood texture: (you can turn the field "mirror" on, so the texture always fits perfectly together, without seam):
Now let's turn the funny blue-white cube on, and then copy the texture to the table (the cube has to be turned on, to make the texture visible)
But.. what's that? There's no texture on the table, how can that be? Did we do something wrong?
No, everything's right, we just have to set an UVW Map Modifier.
Let's use the following options:
Hmm, not that bad. Is it?
So, now there's a simple trick, to let the models look nicer. We render the model. Therefore click on rendering:
Then this window appears.
I won't explain, what the every single field means now, just the most important:
Width and Height control the size of your picture in pixels.
At "Files" you can save the picture.
In Viewport you can choose, from what viewport the picture should get rendered.
After clicking on "rendering", you see, how the picture gets build, how does it look? Well, this is only simple modelling, so, don't worry, I'll make an advanced tutorial, too. :)
But there's still missing something, hmm...