0. Find the tablet located in a chest. 1. Take the earthen jug from the fountain and fill it with water. 2. Place the full earthen jug on the altar. 3. Kneel before the altar and pray. 4. Take a single sip from the earthen jug 5. Take the earthen jug. 6. Dump the remaining water from the earthen jug into the fountain.
If you want any other info than that then be SPECIFIC.
That isn't all there is to it...scattered around the forest are several tombstones...inspect them all but don't disturb them. Thenyou can do the Elven ritual as mentioned when you come to it.