I am beginning a serious attempt at a first novel.  I never envisioned myself as a writer, or at least not as a writer of anything beyond the occasional poetry.  My book has been brewing in my head for some time, but I've only put it to paper in starts and stops.  The scope of the story has grown so much that I feel almost like it follows me around and I have to get it out.  Dramatic, I know, but there it is.  The first thing I wonder about, and ask for some opinions on, is the way the story comes to me.  Sometimes it feels as if *someone* sort of narrates it in my head, and that I am coming to understand the story from some source outside of myself.  I guess what I want to know is wether or not others 'write' this way, and how to utilize it best.  The second thing I am trying to decide is wether to keep it in third person, or to try to shift it into first.  Any advice, opinions, etc.?

Angie

My advice is always just sit down and do it.  Write a lot and give yourself permission to write however you like and however whatever you are working on needs to be written.  In other words, don't judge yourself when you are writing or worry about qualitative things or whether you are doing things right or wrong.  Just write.  Especially as a new writer, I think it's particulary important to get stuff down on paper (or digitally!) without being all over yourself. 

It sounds like you have a story that's itching to be told, which is fantastic.  I would just sit down and start.  Amuse and entertain yourself.  My great flaw is geting bogged down in editing as I go.  I really try just to geep writing, keep moving forward.

. If you get stuck writing the book, then write something else to keep the juices flowing, and then get back to the book refreshed.

This is fantastic advice.

Write what you feel..Are you feeling angry, sad, happy, romantic or giggly? Write about it.  Some days you will feel like doing the plot, and others you wont and those days are perfect to write down what you are feeling. 
Have an idea, or ideas? Write about them, do a basic outline.
Have a character in your head? Write about them, write a letter to them or from them to you.  One exercise I found very fun was, get a character to write about YOU, like it was a forum post asking what you are like as a writer and why they were created.
I met an author who has won prizes and written many books, he gave a talk on his writing methods and told us that we should never throw things out. Just store them away until the idea forms more completely in your head.

Like San I am willing and happy to help people with writing, I belong to a few online writing groups and do insance challenges throught the year.

My big piece of advice- do not give up, ignore those who tell you to stop and write everyday!

Writing for writing's sake is DEFINITELY an important habit to develop.  Whether it's my journal or just a few notes scribbled on scrap paper, I've got a bit of a compulsion to write throughout the day, and I find the more I give in to those inclinations, the better my writing gets.  The two most important parts of exercising my inner writer have been patience and persistence.  You just need to keep at it, and be forgiving when it seems you're not getting there quickly enough.  I think writing definitely needs to be approached as a discipline, and anything I can do to satisfy that opinion is in my best literary interest. 

When it comes to perspective, everyone's got their own style suited to their unique view of literature and even reality.  I prefer the third person with characters' thoughts in the first person, probably in italics as Herbert did in Dune.  A lot of my favorite authors write this way and it's with this perspective that I'm most comfortable.