Question 1 -
Go to
www.apple.com and click on the Support Tab;
On this page in the upper right of the window under search type in
"Streaming Video for the web"
A list of articles will appear that you can select and read
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The one I recommend to answer your question is
"QuickTime 7: Preparing movies for Internet delivery"
Question 2 :
I believe MPEG 4 will allow both PC's Media Player and Quicktime for the PC to be able to see it.
Regardless if saved as Quicktime FAST Movie the movie will start to play as it begins downloading. PC users can dwonload and use Quicktime to play the movie.
Hope this helps
Best
Mike