All of the Standing Stones

Skill Improvement Stones:

                  The Warrior Stone (Falkreath), Combat skills increase 20% faster

                  The Mage Stone (Falkreath), Magic skills improve 20% faster

                  The Thief Stone (Falkreath), Stealth skills increase 20% faster

                  The Lover Stone (Reach) All skills improve 15% faster

Other Stones

                  The Apprentice Stone (Hjaalmarch) Recover Magicka twice as fast, but twice as weak to magic damage

                  The Atronach Stone (Eastmarch), 50+ Magicka, 50% absorb spells, -50% Magicka regen

                  The Lady Stone (Falkreath), Regenerate health and stamina 25% faster

                  The Lord Stone (Pale), 50+ damage resistance, 25% magic resistance

                  The Ritual Stone (Whiterun), Raises all dead around you to fight for you

                  The Serpent Stone (Winterhold), Paralyze the target for 5 seconds and do 25 points of damage

                  The Shadow Stone (Rift), Invisibility for one minute

                  The Steed Stone (Haafingar), +100 carry weight, no movement penalties from armor

                  The Tower Stone (Winterhold), Allows you to pick the lock on anything, once per day