Word count, or how long should your novel be?

Photo by Joel Robison

Per your request, I will attempt to shed wisdom on something which I'm still discovering for myself, namely, how long should a novel be? How many words? I don't have a specific number I'm adhering to in my novels, rather, a certain feeling I have gathered from reading books, primarily traditionally published. I would imagine this topic is more of a pressing issue for self-publishing authors as we have no team of professionals to rely on, somebody who can tell us how long...