These three rits are essential forseeing and teleporting to distant places.
With Remember Place you can "remember" room you are currently in on some item in your inventory.
If you perform Divine Hand on item with remembered place, you will teleport there. If you perform Far Sight on it, you will see this place for a moment, exactly like with "look" command.
Some place prevents using Remember Place or Divine Hand rit, that includes some rooms in temples, for example. Some rooms can be remembered and farsighted, but can't be divinehanded to - like player shops or Bes Pelagric family estates.
If you use Divine Hand, all creatures that follow you will teleport with you. That includes your pets and summons. You'll have to pay 50 gp extra for each one. You can take pet on hands and "unfollow" summons to avoid paying their travelling costs. Note that summons will still follow you if "unfollowed", but will not increase cost of Divine Hand.
When performing Divine Hand, you will not go to remembered place directly, but first you will be taken to your deity's room. You'll have to exit that room (you'll have to find a way) to get to place you need.
Remember Place - 30 gp, holy amulet, 24 fa.ri.mi.ta.
Far sight - 35 gp, prayer book and holy symbol, 30 fa.ri.mi.ta.
Divine Hand - 200 gp +50gp for each following, holy symbol, 150 fa.ri.mi.ta.