His Wikipedia entry is here and the biography on his own website is here. The lack of traditional art schools (though the situation is slowly improving) led Shanks to establish his own school, the Studio Incamminati.
Shanks gives numerous demonstrations. Charley Parker writes about one here and Matthew D. Innis provides a more visually detailed example here.
The Wikipedia link includes a good deal of information regarding Shanks, including a number of quotes. The one I found most intriguing is : "I almost never do drawings, because I have found over the years that doing something in one medium and translating into another doesn't work. I like to conceive a painting in real scale and in color."
Here are examples of Shanks' work.
Shanks is best known for portraiture and other depictions of people -- especially women.
But he's competent with landscapes and still lifes as well.
And he pays a lot of attention to color. Note how the warm areas are set off by cool colors at the top and bottom.
About half of this painting is neutral background. Which helps us to focus on the rest of it.
Shanks painted several works featuring a low-positioned candlelight effect. Just because one's work is representational doesn't mean that it can't be interesting or creative.
Papal portraits almost always seem to feature their subject seated. Here Shanks has John Paul standing. And the gesture, to me, makes this one of the most outstanding papal portraits of all; it captures the man.