Inscriptions-Armor and Weapons

I've just gotten Nightfall, and to be honest, I haven't played it much, I'm kinda used to Ascalon, but one thing I need to know about is the Inscriptions for Weapons and Armor, because I can't find it on the site anywhere. So if someone could explain them, on the assumption I know nothing about them, I'd appreciate it.

Basically, more customization to your liking on weapons, which is a bad thing to some people apparently.

Is the effect global for armor? or just for that one piece? and is there any place I can find a list of Inscriptions and their effects?

Inscriptions are for weapons. http://wiki.guildwars.com/wiki/Inscription
Insignias are for armour. http://wiki.guildwars.com/wiki/Insignia