Many university Computer Science courses stress at least the basics of computer architecture early on, it's a good way of showing how learning crap like binary addition and division is actually sometimes useful.

You'll also get a ton of information on data pathways, how buses work, memory, input/output control etc.
The textbook I used personally was called "Principles of Computer Architecture" by Miles J. Murdocca and Vincent P. Heuring. Being 1 am I'm not going to scrounge around for the ISBN number but I can do that as well later if needed. Actually, most of the material is online in Acrobat format at:
Slides: Principles of Computer Architecture
http://www.cs.rutgers.edu/~murdocca/POCA/slides/
Good foundation on the nitty-gritty of computer architecture today, and its history.