After installing Ubuntu, most users get some must-have packages like audio/video codecs, flash, ms fonts etc... but you need to be online to install them. Linux mint is basically ubuntu + those packages, so you can make a complete offline install...
also, make sure to get
this, very useful :)
hey and keep in mind that the easier the distribution is, the less you learn. you don't want some GUI to do everything for you, it destroys the whole purpose of linux... i suggest you get started with debian (the distribution from which ubuntu is derived). the package manager is great, and they also have a netinstall, which lets you install the operating system package by package which teaches a lot... also, the community is great, the freenode channel is huge, and there are thousands of docs online.