Runepriest

Runepriests are keepers of the art of Dwarf rune-magic, adepts and sages who spend their lives learning the language of runes. With their craft they can unleash the power contained within these runes, improving their regular abilities and providing protection to their allies.

Runepriests are ideally suited to group situations, but must carefully balance their offensive and defensive actions to ensure that they can bring enough of their considerable powers to a fight while still managing to provide support to others in the group.
 

Path Of Grungni

A master of this path focuses on powerful and direct effects, learning to both restore his allies and smite his enemies with equal skill. The path of Grungni is for those who prefer to focus on a single target at a time, be they friend or foe, and unleash powerful effects upon them.

Path Of Valaya

An arguably more subtle mastery, the path of Valaya is focused on effects which continue to linger after they've been invoked. A master of this path prefers to stick to tested, tried and true slow-and-steady abilities, whether he's building up his allies' strength until they become unstoppable, or whether he's grinding his enemies down with inevitable and inescapable doom.

Path Of Grimnir

This path is concerned with runes which affect large, sweeping areas as they unleash their innate power. A specialist in this path is an expert at changing the ebb and tide of combat by either bolstering his allies' entire front line, or by sending vast swaths of crushing power across the enemy masses.

Information found at: http://warhammeronline.wikia.com/wiki/Runepriest