I know its was not easy for me to switch from xp to linux(ubuntu). The first thing that made me difficult was that there was not any type of media-player that could play my mp3-library. Though there was totem movie player it didnt played my library due to missing codec.
The next first thing that made me difficult to use linux was the name given to applications. Most of them were irrelevant for me. Lets take "amarok", it didnt have any significant meaning (at least not for me). I heard its name from my friend and got to know that it was audio-player.
There were so many of other problems i faced that include burining a disk,installing from tar.gz or tar.bz2 by making own compilation, or using internet, etc
Though i found it a bit later after i switched to linux. This link was very helpful for me.
The Linux alternative project