The Robin Williams' suggestions are good. I'd also recommend something by Steven Heller.
This might be a good starting point.
That's going to give a less dry overview than something like The History of Design by Phillip Meggs.
This is a little bit more business oriented but a good way to understand the actual career side.
Like Jim posted above, Communication Arts was (and still is) one of my biggest sources of design learning. When I was first starting out, it was Comm Arts that really helped me to sort out what was good and what was bad (which at that point was basically everything that I was doing. heh.)
