Tracing the signal from source to speaker

Hi all,

I'd like to get a better understanding of what happens between a flac file and the sound coming out of a speaker in a digital environment. If any of you can provide insight or point to references for the following, I'd appreciate it. I want to be able to explain this signal path in semi technical terms so that any of us can understand what is happening. To wit:

1, What does a player do? It must acquire (via index) a file of various type, consume it, and output a digital signal. What is the transformation, and what is the type of signal that emerges?

2. What does a DAC do? It takes the digital signal and converts it to an analog signal. What is this conversion? What is the difference between the digital and analog signals?

3. What does the preamp do? What are the differences between preamp processing that create a different type or quality of signal out?

4. What does the amp do? What is the signal out made up of?

5. How do passive or active crossovers recognize the difference in incoming signals?

6. How does the speaker respond to the incoming amplified analog signal?

At some point I would like to include a high level explanation of how the player sends a signal through a switch and router to a NAS (or even a remote service), and how the NAS responds. 

I see this as an 10-15 page ppt explaining the functional processes of the digital audio chain. Any help would be appreciated.

Thanks
Chuck