Your download time will depend on exactly which version you want, and the speed of your internet connection. Most versions are between 100 and 200 megabytes, so a download on a reasonably fast DSL...
It depends on your connection speed, primarily. On dialup, it's going to take quite a while to download. On broadband (Cable or DSL), it usually downloads for me in under 5 minutes.
It depends on how fast your computer is. On my laptop it only took around 15 minutes to download. But on my aunts computer it took around 45 minutes. It truly depends. Just remember that patience is...