With my internet, 100mb, I can download the games from torrents (if they're well seeded), or directly from some websites, and it can take like 10mins or less, for a 4gb game.
Now, if you download them via sites like rapidshare and etc, it'll take ages, unless you're premium.
As for ripping, I always burn my games at 4x, so it takes around 10/20mins, depending on the size.
Like Supr said, there really isn't an average, just check what's your internet speed and how long the sites you use take to download the files.