"Our greatest pretenses are built up not to hide
the evil and the ugly in us, but our emptiness.
The hardest thing to hide is something that is not there."

- Eric Hoffer

Hiding is an extremely usefull skill if you PvP a lot. But it's also a life saver when hunting monsters, especially for bards, treasure hunters and lockpickers. It allows you to make yourself invisible to players and monsters alike. And unlike the invisibility spell, there is no time limit on the effectiveness of hiding. You will remain invisible as long as someone else doesn't reveal you with detect hidden or tracking skills. Note that some creatures have the reveal ability, such as the plague spawns, ice elementals, ninjas, ronins, white wyrms, etc. IF you are targeted by those creatures, make sure you do not hide in the same screen they are on. If the line of sight isn't broken, they may very well (and likely will) reveal you). Once you hit 50 hiding, you can start training Stealth. This skill allows you to move around while hidden. It is a great skill to have if you hunt in Fel dungeons or are involved with factions.

This is an extremely easy skill to train. All you have to do is hop on a boat and use the hiding skill doing 8x8.