Making up Names for Fiction Writing

It's the bane of my writing existence, really.

Naming things and people. You would think it would be easy since pretty much anything goes...but no. It's not easy for me. I know I can just make things up, but there's always this nagging voice in the back of my mind saying, "If this book takes off, do you really think that's the best name for this character?" Okay, so that's probably a huge part of my problem - always worrying about what other people will think of my choices if and when I ever publish a novel. I guess understanding the problem is a huge step, but it doesn't exactly make it easier either.

In my current WIP (work in progress), I need to name three major things.

1. The evil Sorcerer (nothing will ever be as cool as Voldemort! How can I come up with anything that could compete, but not sound like I'm trying to copy JK Rowling?)
2. The alternate dimension in which the magical people live. (Originally, this was going to be Pandora. Brilliant, right? Then freaking Avatar had to come out and be the number box office hit of the past 10 years - featuring an alien planet called Pandora. Sigh.)
3. Finally, I need to name the group of teens who act as guardians to make sure the Sorcerer does not get out of his Earthly prison. (Yes, this is a zombie apocalypse book, but with magic :).
   

I try not to let my lack of decision-making when it comes to names hold the writing back. For instance, I will just put Sorcerer as the guy's name (or should it be a sorceress? see? more decisions!) and keep trucking. But eventually, I will have to come to a decision. I wish I could call up JK Rowling or Stephen King and ask them how they name characters. What's the process involved? Or did you just pluck them out of thin air? I'd love to know, but something tells me JK Rowling doesn't read my blog :P.