Memory Adressing

OK, this is not a mac specific question, but I think that you guys will know this stuff. I have an exam tomorrow (so I need help ASAP). It is about hardware in general, including memory addressing, processors and motherboards. The last two I can understand quite well (I'm no hardware geek, I know enough to get around and quite a bit of the software side), but I missed my class on addressing and no matter how much I google and how many articles I read on wikipedia I just can't grasp the thing. All I can find articles that just say stuff like: "A number that is assigned to each byte in a computer's memory that the CPU uses to track where data and instructions are stored in RAM" and that the processor communicates with the memory thru the address bus, of witch I don't understand the physical relationship in between buses (aka "connections"), word length, and the maximum amount of memory a system can support; or stuff like wikipedia which only confuses me more (for example I can get the definition for "address bus" but no explanation to my previous question). What I need is some kind of help to "integrate" one fact with a other. Some stuff I have doubts about: address bus, word length, memory addressing (referring to the cells of the memory), how the processor's fit's in to all this, maximum memory (and its relationship with the word length)...
Thank's in advance for any help, you've saved my ***.

Come on... Please, some help.

I just understood the relationship in between powers of two, the bus width -8bit, 64bit etc- (which I'm guessing is the number of cables) and the max RAM.
For example -from what I understand- a system completely 64 bit (address bus, OS and what more?) would be able to handle up to 2^64 (1.845b). Or a 33b system (as irrational as it would be, since standard word length is 8bit?) would handle double that of a 32b system?
Note: I often use expressions like: "(address bus, OS and what more?)" to express that "what more?" is a question. Sorry for my bad english.

Well, never mind. Thanks for the help. Really, I was expecting a little more compassion. Do you remember back when you had exams? I guess not. Not everybody is lucky enough to have finished school.