This is quite an eclectic mix, in no particular order (except I know the authors of the first two, so I put them first as a plug). I own most of them in print.
A few more from my books-to-buy list (recommended by others):
[Y]
The Art of the Icon: A Theology of Beauty, by Paul Evdokimov (Oakwood Publications, 1989)
This ought to be good, and Logos really needs something about icons. Now that I look, I can't find that they have anything. Big mistake!