When it comes to Computer Architecture what is old is new again. You have to learn the old part before you can comprehend the new part.
You might ask what is it in computer architcture you need to learn. Computers are Circuits so one thing you will need to learn is what are computer circuits and how do you draw them and read them. This is really basic gates and switches. An example might be the logic to perform a simple add and subtract or how to build a circuit for memory.
Then they will get into the layers of hardware 7 I think. Maybe one more than that. What are the layers like Logical and abstraction hardware software etc.
Then there are actual components what is a gate and what is used to make one. How is a gate or transistor constucted. Name 3 types of Transistors.
You can imagine hardware questions and terms for hardware. Standards Committes, organizations, terminology.
Then there is an inebidible section on how does base 2 work and if a processor is 8 bit how many bits can be read at once?
Then there is a processor how does it really work? What are its parts, what is a cycle and a bus, and does a processor have a clock? If so what makes it tick? What are all those lines going to and from the processor?
PATA, SATA, SERIAL, PCI, PARALLEL, EIDA, ATAPI, FDD, ETC.
I would just go to Amazon and look for books. They will have the most common books used for teaching courses. This is a very laborious subject and only really interests people who do design work for processors and odds and ends like that. I have never had to read an electrical schematic to do my job, so basically what you are learning is the theory behind how computers are built.
You could learn more intersting books like
Where Wizards Stay Up Late by Katie Hafner and Mattew Lyon about the development of the Internet from the days of Eisenhower, or Accidental Empires by Robert X Cringely wich covers a kind of a history of the PC Industry From the Altair computer to the likes of computers up to about 1995.
Without know what is going to be taught it is hard to say what book is best. Sometimes the university has a online bookstores or multiple bookstores that can tell you what book will be used for the class. It would be nice if you could just go to school early and see what book will be used for the class and buy it and take it home and look at it.