Thinking About Writing a Book

I am thinking about writing a book. I just have so many things I have to figure out to make that happen. I'd like to design the whole thing -- page size and layout and all that, but I don't really want to be in charge of distribution. I also need to, uh, kind of figure out WHAT I want to write about.... I have no idea about how I get published (or if I want to publish myself) or how to set up copyright things. If someone out there wants to give a few pointers, I'd appreciate it.