can somone please tell me where to find one of the stoned that allow you to pick your sign?

I have played for a about 8 horus now and i havent found one yet. I am doing alright but i could be so much better if i had the boosts from the signs

There are 3 of them - Warrior, Thief and Mage - along the road between Helgen and Riverrun, near the road at the bend just before the river. The Imperial guy I was following stopped and pointed it out for me, didn't go on until I'd picked one. Others are all over the place.

There are not just 3 there a more, you just have to find them.