The Two Courts

There are two main courts in the Feywild - the Summer and Winter Courts. Think of them a little bit like countries. For the most part you'll be traveling in the Summer Court, but on occasion you'll cross over.
The Summer Court:
The Summer Court is what mortal races might traditionally think of as 'good.' The sky is brighter, the plant life more colorful, and the people friendlier (at least, on the surface). I know I've emphasized this in previous entries, but diplomacy is your best option here for getting what you want. Flattery and gifts will get you far. But, be careful with your words. Like I said, people are sometimes only kind on the surface. They will take any opportunity they get to twist your words and swindle you.
This court is ruled by Queen Titania. She tends to be distant, not concerned with trivial matters, unless you kill something sacred to her. Then prepare to be... Smited? Smote? I don't know. Anyways, this includes most deer, and some other random things. You never really know, so refer back to the basic rules - don't kill unless it tries to kill you first.
The Winter Court:
If you somehow end up in the Winter Court on accident, get out of there as fast as you can. You'll know from the dim skies, rocky terrain, creepy glowing mushrooms, and general ominous vibe. Creatures here are much more openly hostile, trying to steal from or kill you. Keep your coin purse close and your magic items closer. Especially towards the edges of the court, darklings and boggles are a huge annoyance. And if you thought plants were dangerous in the Summer Court, you're in for a whole other story here.
The Queen of Air and Darkness rules here. I don't know much about her, but she is much less caring than Titania and seeks power for herself.
One last thing to note about the Winter Court. Time can move strangely in the Feywild no matter where you are, but the effects tend to be amplified here. An hour in the Feywild can equate to a few seconds or a few hundred years on the Material Plane, or anywhere in between. I've never seen anywhere near the latter, and I sincerely hope none of us ever do.