My hearth where I create with words and images.
"In the shade now tall forms are advancing,
And their wan hands like snowflakes in the moonlight are gleaming;
They beckon, they whisper, 'Oh! strong armed in valor,
The pale guests await thee - mead foams in Valhalla.'"
- Finn's Saga
Valkyries are female spirits of battle who serve Odin. The name valkyrie means literally "Chooser of the Slain". They apportion victory in battle according to his commands, and scour the battlefields for those who are particularly brave, or show particular skill in the arts of combat. When such warriors die, the valkyries then carry them over Bifrost, the rainbow bridge, and to Valhalla. Once there they also serve the slain warriors meat and drink. (This should not at all be seen as a servile role, rather just the opposite. Sometimes in viking society a queen would serve a particularly honored guest herself, as a sign of great respect, and it is in this sense that the valkyries serve the einherjar who feast there.) Another function the valkyries serve in Valhalla is to guide the warriors in their battle-training, and to heal and/or reanimate them after a day of battle-practice. When the Northern Lights were in the sky, our paleopagan ancestors said that it was caused by the light reflected from the shields the Valkyries were beating their swords against.
But there is more to their nature than this. Valkyries are sometimes seen as imparting deep lore and wisdom to certain humans, as the valkyrie Sigrdrifa does in the poem Sigrdrifumal. This lore seems to be concerned with galdr, and with battle, and with right conduct. Valkyries are also seen as providing protection for certain favored warriors either directly shielding them in battle or providing warnings or protections in dreams, such as one warrior experienced when he dreamed a valkyrie removed his innards and replaced them with straw, to render him invulnerable in a coming battle. They also give warnings of battle via dreams and visions, and also of impending death.
It seems that in certain cases, the valkyrie might become identical with the fylgja entity (see the article on Asatru). In such a role, the valkyrie guides and protects her chosen human, and may become his lover. She teaches him the ways of Odin, and brings him wisdom and inspiration from the god, and when the time comes she kills him and brings him home. This kind of relationship can be seen in the Volsunga Saga, between Sigurd and Brunhilde/Sigrdrifa, and in the Lay of Helgi, and hinted at in the story of Wayland.
Taken from the website: http://www.uppsalaonline.com/uppsala/valkyrie.htm