Read Wagnard's thread on how to play a rook
http://forums.demigodthegame.com/337806
Warp stone allows you to teleport a short distance. You can buy it at the item shop right next to you in the beginning of the game.
I notice in the latest beta3, rook seems weaker in the beginning, or maybe the other demigods are stronger. Once rook gets to level 6+ where you have bolder roll. Then rook becomes uesful, because it's hard to land the hammer slam without boulder roll.