As far as I know the best GUI tool to mount a disk is come with Gnome, which is the Gnome-Disk-Utility. If you want to run it from terminal, the name is kinda weird as it is completely different from its name - palimpsest
By using Gnome-disk-utility, mounting a disk is just two steps:
- select the partition
- click on the "Play" button shown on the right screen.
- Voila! (well, this is not a step, so... two steps, ok? =P)