What are the essential must-read and industry magazines in the design world? (printed)
There really aren't any as far as I know. CMYK magazine is kind of a joke. GD USA seems to be mostly ads for print services, and some misc articles, but I've never read anything in it that blew my mind.
What should I expect to find on a coffee table at a high end design house?
I honestly couldn't say. If they have a stack somewhere, it's more than likely all the same magazines you find in barnes and noble's. (Layers, CMYK, Computer Arts, Netmag, there's a half a dozen just geared around illustrator and photoshop, then much more when you include photography magazines)
There's definitely a certain beauty in a vibrant, printed medium. I used to read the netmag magazines, and honestly, 75% of it for me was just the eye candy of their printed layouts. They had good articles as well. CMYK on the other hand, I've never seen anything worth reading in it. It mostly seemed like, and pardon my friench, but print designer circle jerk. (if someone has a less vulgar term for that, please comment and I'll edit this)
In summary, go to a bookstore (a big chain one, like barnes and nobles or something) and check out the computers and art sections of the magazine area. You'll find some to check out. However, I don't think there's any must read magazine that holds all the latest secrets of the industry. Especially since in many ways, print magazines are steadily on the decline. I'd imagine especially so since in the last year or two it seems that lay people have become accustomed to using tablets or e readers everywhere they go.
What I personally have done in the past: when bored, go to borders or some other book store, grab a coffee, and sit and read the magazines. The articles are short enough you can pull it off, no one's going to question you unless you do this every day at the same time. Besides, those magazines ar like $20 - $30 each. Significantly more for the "bookazines".