Hi there,
well this one is really easy. You just have to keep in mind, that materials are not textures. I mean the simplest way to attach a texture to an object is to use an image file and connect that one to a material. So you would open the Hypershade and do a
CODE
Create - File (section: 2D Textures)
which results in a texture as you probably figured out already. But then you have to create a material that you will connect with your texture.
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Create - Lambert (section: Surface)
Now you just drop the texture onto the material (Ctrl - MMB) and you assigned the texture to the material.
Now select the geometry and MMB-drop the material onto the selection.
If you want to "delete" the textured material, just assign the standard lambert1 to your geometry. You shouldn't connect any textures to that though. That was easy, was it? A hint: A nice book about texturing does no harm.