The Linux desktop environment has made great strides in terms of usability in the past couple of years. In that light, I present Rhythmbox, an OpenSource music player ala iTunes for the Gnome desktop. Some of its features include an iTunes-style layout, search box, playlist management, podcast handling, and iPod integration. If you learned iTunes, using Rhythmbox will take only a slight adjustment, mostly involving a minimally different look-and-feel.
Thanks to the power of apt/aptitude/synaptic, installation should be a breeze:
$ sudo aptitude install rhythmbox
When complete, take a gander at your Applications → Sound and Video menu. Select Rhythmbox Music Player and you should be in business.