Research on Faerie
Faeries are magical beings residing in the Nevernever. They are a very heterogeneous group, as there are many different kinds of faerie. Some of them are humanoid in their form, some like animals, and others like various monsters. Many of the faeries belong to one of the two major Faerie Courts of the Nevernever, the Summer Court and the Winter Court or the off-season and overlapping Autumn Court and Bloom Court. Those that do not belong to one of these are the Wyldfae, though they too, have their own factions and organizations.
The concept of a debt and obligation is a huge factor in how the fey behave. The Sidhe are unable to give anything away for free. There must always be balance. Never take anything without giving something of equal value in return. Never give a favor without getting one in kind. All of Reality depends on it.
It is generally tricky and dangerous to ask the Sidhe direct questions. Questions that deal with conflict especially may receive obscure and maliciously misleading answers. They are, however, “fanatical gatherers of information and guard their information as ferociously as a dragon guards his gold”. Information is more valuable than gold.
Faeries are often insane, mischievous, and very dangerous, but they are also good to their word. It is possible for faeries and humans to produce offspring, who are called changelings. Sidhe cannot speak an outright lie. They are, however, very adept at word plays and the twisting of meaning and literal speech.
As part of their magic, they can use glamour to change their appearance. They’ll try to put a mortal off balance with their beauty.
Faeries are vulnerable to cold iron, which is deadly to them. Running water does not appear problematic for the Fey.
Note from your GM: More research avenues available including Faerie Deals and Faerie Politics