To get you started, here are some examples of what you can do with the wiki. To see how these work, edit this page and take a look.
If your character has no slug, you can use the ID number, like so:
For PCs and NPCs in your campaign, you can just use the PC/NPC Link Lookup in the sidebar to the right. It’s quite handy!
HTML and Textile
To style things how you want, you can use either HTML (with some restrictions) or a simple formatting language called Textile. It’s up to you, but Textile is pretty easy, while simultaneously allowing for lots of customization.