I do enjoy a good, open-ended question, so thank you for asking! Though, it is still a bit of an informal post on my behalf, but still it should be worthwhile.
The Valkyries are quite an interesting feature in Norse and Germanic mythology. They appear quite frequently in literary sources, from the Eddas to the Sagas. Given that this is such a huge topic, I will provide a little taste of a few things I have encountered, which should be interesting. (I actually will be including the Valkyries in my next crash course lesson next week, but this post will have a bit more detail probably).
Valkyries are fascinating. I always love seeing a kick-butt, strong woman figure (especially in a historical context). They are a powerful force that have many responsibilities and have great influences. They are quite active in events and are rather common in literary works. They also provide a “role model” for powerful, non-supernatural women. They are the famine rendition of the berserker, and equally frightening to face (if not more so), mind you.
It is always best to start with some basics (not all know about them too well). The Valkyries are women who serve in Valhalla. They are sent by Odin to the ravaged fields of war where they decide the fates of men; who shall die and who shall rise to Valhalla. It is said in the Prose Edda that the youngest norn, Skuld, also rides along with to decide. Norns are similar to the Valkyries, shaping the lives of men at the Well of Urd. Though, there are more than just those in Asgard.
I will continue by discussing some references to Valkyries in primary sources such as Volsunga saga and Njal’s Saga. There is some rich insight to be had when seeing their symbols and characteristics in practice. This is a somewhat long post, so if you’d like to keep reading, click below. I at least recommend checking out the poem from Njal’s saga, if you are interesting in Valkyries (see below).