It is hard to suggest where to get started, without knowing what you know. You absolutely MUST understand, thoroughly, those technologies listed below, before you will understand anything in the design of an electronic system.
I am trying to give a decent outline of what is required to meet your goal, but, I am not sure of how in depth you really want to go in "design." Some people will say "design" and mean, "just throw something together, and call it there own". For example, some people, and computer builders feel that they designed their computer, and their customers computers, by looking at their wants, and picking out from Newegg the parts. Therefore, I will just give a basic outline of what is required to actually get to the point of fully understanding any electronic system. I cannot possibly see how anyone could understand the design behind a basic electronic system without knowing these.
If you are trying to REALLY learn the nuts and bolts you'll have to find a "Computer Organization/Architecture" book. It's going to take you down to levels of AND, OR, XOR, and NOT gates and understanding schematics for a circuit board. It will also give you a good understanding of what goes on during each CPU cycle and an overview of the instruction set architecture. Unfortunately, I don't think it will be possible to learn the "nuts-and-bolts" without getting pretty technical.
Couldn't agree more.
edit* After righting for about 20 minutes on a list, I realized it would probably be better to just delete it all, and just ask first:
What all do you know?
How do you define "design"?
I dont have a clue as to what "A+" is, but maybe that will help.
Otherwise, I would suggest googling "computer system" or "electronic system", and researching thoroughly any and every word, concept and idea that you dont immediately understand.
Well.... I have learned in the meantime that A+ Certification is a basic computer repair/upgrade/build certification that is actually required by a LOT of companies for their people/technicians.....
I have been slowly scouring a copy of Scott Mueller's "Upgrading and Repairing PC's"..... which has been a GREAT book.... but in some ways... is almost a part's catalog of darn near EVERY computer component ever made for a PC.
I read MaxPC, Computer Power User, Computer Shopper, PC World (on occasion), PC Format (a British PC mag) and a few other mags on a regular basis..... and have learned a bit from there and here.
I'm not looking to design.... but I'm looking to understand how motherboards are laid out.... what the various components of a mobo are wand how they all interact.... individually and "globally". How CPU's really make their computations work and what all the timing issues are.... how electricity goes through a CPU and makes all the transistors create the results we see.
Does that make any sense? I know that a GPU is the processor that generates the graphics for a video card and that the video card connects to the mobo and that the two devices communicate through a "bridge". But, my questions become.... how does the bridge regulate/control that data? How do the two communicate with each other? How does the GPu differ from the CPU? I am somewhat familiar with the fact that the two are different and that GPU transistors are very "task oriented" while a CPU is more flexible.
I managed to survive my first year of the engineering program at Univ of Cincinnati before transferring, so I am familiar with the basic functions of a circuit to a degree. I finished of my second year of engineering school before going broke and joining the Navy.... that and I was a Mech-E... not an electrical engineering or computer engineering focus.
Mind you.... that was all almost a decade and two tours in the Middle East ago..... so my education is rusty.
I've found Scott Mueller's book to be FASCINATING..... but it doesn't go enough into how the parts themselves work. He does discuss a lot about the various features on things..... but I'd like to understand more about how exactly these devices work/function.
Does that help any????
And yes..... I plan to pursue my A+ Cert.