I am intending to dual Ubuntu studio with Vista (already on the computer). I am told by various online tutorials that I need an internet connection while installing Ubuntu Studio. I have installed the ISO file and burned it to a DVD. Does the installation process download more files for the OS and if so, how much?
Ubuntu itself is an OS that heavily depends on a internet connection. All the repositories are on-line so installing software and updates are done over the internet. Our dash keeps getting things like webapps, internet searching (ie. amazon) and so on that all expect a permanent internet connection to get results.
During installation the system uses your installation media but can use the internet to update those files or install restricted software (like mp3 playback). Studio itself is aimed at the GNU/Linux audio, video and graphic and restricted formats are more than likely not available on the installation media (since it would be a copyright violation) so you will at least once need an internet connection for that. During that one time you can also update your system.
In short: yes you can install and use Ubuntu Studio without an internet connection but it is a lot easier if you do have one.