Is it supposed to look human or alien?
Always an important thing to mention when posting something that could go either way. Human, Alien or Cartoon?
Without knowing the intended use, it’s difficult to accurately crit a head model. That said, some fundamental anatomy usually applies across all possible character types.
I would recommend looking up some profile pics (portrait websites are good for this) to see the actual shape of a human head. From these you can exaggerate the features but maintain basic accuracy. By exaggerating features differently, you create different characters with underlying similarities and so maintain a consistency throughout your production.
Your wire model shows some nice meshwork on the nose and eyes but if you plant to make your character speak or pull faces, you might have difficuly with the complex mesh around the mouth. This is one area where good loops make for good deformations.
If you look at the Orange Guy you’ll see a loop runs from mid-nose around the mouth and across the chin with other loops contained within. You don’t have that basic structure that applies to almost any creature with a movable mouth.
To drive your shape keys is fairly easy. To copy the widget method used in the ORange Guy you are probably best to find and download GuitarGeeks widget script (I think there’s a link on the site where the Orange Guy is).
To do it yourself, make some shape keys then create some simple, separate objects to use as drivers. Then select your mesh, go to the IPO>Shapes select a shape key from the list, bring up the data panel (NKEY) and press Add Driver. Link it to an object and choose from the list what object transformation will drive the shape. IF you chose something like RotZ from the list, then grab your chosen driver, rotate it around Z and watch the shape deform. Sounds complicated till you mess with it. It’s surprisingly easy if you understand shape keys to begin with.
Then you arrange the driver objects on a separate layer and view them in a separate window - unlocked from other windows so the view remains fixed on only that layer and you can hide this layer in your main scene window. This way you don’t have to keep looking for your drivers and they don’t keep showing up in your scene.