It all depends on the size of the file, and your internet connection. ISO files are large compressed image files used to boot CD/DVD's and there installed files. They can be up to 10 gigs easily. With a 100KB line, 4 gigs will take a few hours. With a 5KB line like dial up it will takes weeks.
so dificuly
You need a burning tool to do that so. You can download any of several free ISO burners. (See related links)
You can download as many as you wish, however they will download in a queue, so first you choose will download first and so on. They are small files so will not take long to do.
About 2 hours or so
because it does, okay VAG head?
Because it is such a big file (Over 2GB)
You can download the MYST ISO file from many different torrent sites. As it would be illegal to do so, I can't post a link for it here. Remember: Google is your friend!
This depends on your pc. mine wasn't so long because i have a advanced pc.
Try joining so you're not looking at guest pages
Downloading minecraft is super fast, depending on your internet speed. As a personal experience, a school computer running at 70KBps could download it around a minute or so, so it doesn't take too long! However, a faster speed internet could download it in under 30 seconds!
Because apple fanboys kiss mine
so far for me about 6 hours, but my internet is very slow.