On the left of the hypershade, click where it says "create material" and then chose "create texture". Or if it says "create all nodes" then just scroll down until you find "2D textures".

Now, click once on "file" (which is under 2D textures). This puts and empty file node in your work area. Now while that node is still selected go to the attribute editor and look for "Image Name", then click the folder icon next to that text box and that will open an open file dialog, look for the picture that you want to use as your texture and then click open. You should be able to see the picture in that file node instead of the black square.

Now, if you don't have the blinn node in your work area drag it there so that you'll have both the file node and the blinn node in the work area. Now, with the attribute editor open, select the blinn material and then hold the middle mouse button over the file node and drag it to the color attribute of the blinn material. Your blinn should now be showing the texture instead of a gray sphere.
Apply the material to your textures and you are all set.

Of course this is only one way to do it. But I won't explain other ways because it's late and I'm sure u'll be ablo to figure them out on your one after some meddeling in Maya.