Who's Afraid of Novel Writing?

I am.

That MFA diploma certainly doesn't mean that I know anything about writing a novel.  Oh, I've read them, sure.  So many, in fact, that all I have learned is that anything goes.  We have great expectations for the short story, but what do we want out of novels?  Or, I should ask, what will we accept from a novel?  Seems to me that we will accept any format, any premise, and any ending, however implausible, as long as overall the book is well executed.

How, then, can I possibly sit down to start such a thing.  Not just sit down to write, but simply start.  Do I have any idea what I'm doing?  How much do I have to know before I start?  Should I have the whole thing sketched out, or is it okay to just go on an idea?  Given all these questions, do I really want to commit myself to such a thing? 

I am a busy man.  A full time job and a one year old child.  Not as busy I have been, but how much time do I have to devote to writing a novel?  Can I really commit to these characters, this story?  Do I really want to work on a single project for the next year or more?  It takes me months to finish a single twenty page story; at that pace this could take me decades.

Never the less, I am going to do it.  I writing out some character sketches now, and then it's time to begin the pivotal first chapter.  Wish me luck.