You're here. What to do?
Explore a little. You don't have to register, but if you do, you get to post and customize your dKos homepage.
The signup process asks for an email address, where your password is mailed (you can later change that password). I don't and will never use that email address (I don't even know where they are stored in the database). It's simply a way to keep trolls from hijacking the message boards. You can always create a temporary Hotmail account or something like that if you are afraid of giving up your email address.
Once you signup, you can set up your user preferences (your public profile others can see), your display preferences (customize your dKos homepage), and even create a Diary -- a mini-blog on dKos.
If you see any weird-looking pages or anything breaks, please send me a detailed email and I'll work to squash such bugs. I don't doubt things will go wrong, so please help me fix them as quickly as possible.