In RuneScape, to train up the skill prayer, a player needs to bury bones. Almost all creatures drop bones when they are killed, except Scorpions. When a player buries these bones, they gain 4.5 prayer experience. Some good places to get bones to bury follow:
Lumbridge: Level 2 Men and Women both drop bones, also often with coins.
Cow Field: The Cow Field near Lumbridge often has lots of bones laying around, or if not, it has cows which always drop bones.
Chicken Farms: Chickens only have 3 hit points, and so make easy targets for bones.
Stronghold of Security: To get to the Stronghold of Security, get to the Barbarian village by going through Varrock. If you don't know where to go, refer to the world map. Go down into the Stronghold of Security, and pass through the first few gates. You will need to answer a few questions about security, but they are not that hard, they can be answered by common sense. In the SoS there are four levels, but you will only need to stay on the first one. Run past the goblins, and in some of the passages between the larger sections, there are groups of Rats. Normal rats don't drop bones, but the ones done here do. The rats only have 2 hit points, plus you can't be attacked by the monsters.
Big Bones: Giants and Ogres drop big bones, but for hitpoint per prayer xp, they're aren't any better than normal bones.
Remember to bury all the bones other people don't bury. Prayer is an important skill for proper Runescaping.