ESO Guide - Mundus Stone Locations : TESO Discussions

There’s a total of 13 different mundus stone, each of them with a different passive buff to your character. Below is a list of all of them:
Lord – increases maximum health
Tower – increases maximum stamina
Mage – increased maximum magicka
Lady – increased armor
Warrior – increased power
Thief – increased critical strike chance
Shadow – increased critical damage
Steed – increased run speed
Ritual – increased effectiveness of healing
Serpent – increased health regeneration out of combat
Atronach – increased magicka regeneration
Apprentice – increased spell penetration
Lover – increased spell resistance
These buffs are scaled in power with your character level, and you can even enchant your equipment with Divines trait to further increase benefits provided by these stones. It’s important to note that activating a mundus stone and its effect doesn’t cost any skill points or anything like that. You can switch them whenever you like without any costs or downsides whatsoever.
source: http://www.elderscrollsguides.com/mundus-stones/