The 'hidden away' rooms and Inspiration

I have recently been feeling inspired by Calista who is doing a 31 Days of Order Challenge for herself and her surroundings.  If you haven't seen it, you can check her out here: A House and A Yard.  It's been inspiring to watch her post pictures of her house BEFORE the order... and her plans towards establishing order in said places.
I have some rooms which are in some DIRE need of serious order.  Mostly cleaning... but also order.  I try to keep the rooms that people see pretty clean and picked up.  I vacuum several times a week, I sweep the floor several times a week, do the dishes daily, stay on top of laundry... and when things get messy, and people are coming over, I put things in the back room.  You know... the room no one sees because you are certain to make sure the door is closed.  Here... I've opened the door:

Looking in the door: the desk, papers, crafts, a printer...and I don't even know

To the right, where I keep my vacuum and the GIANT chinchilla cage I am trying to sell.

A broken bookshelf, a hamper of winter things, a carseat, art supplies, and a dresser full of TONS of things including important papers.

Keep in mind, this room is going to be a nursery in a few months... so not only does this need to be clean AND organized... it also needs to be completely empty of everything in here.  Including the closet: 

Games, baby clothes, baby hiking carrier, work boots, and I think my wedding dress might be in that bottom container... 

It's been quite overwhelming for me to think about... because frankly I don't know where to put everything, also, I'm not very organized.  Clean? Yes.  Organized? No.  I have room mostly, just not sure how or where exactly to put things, or how to organize it all efficiently.   This has been hanging over my head for months and I have to get to it before the holidays and I'm too busy, or afterwards, when I'm just too pregnant and/or need to be setting up the nursery.   So there it is folks... unlike Calista I don't have cool pictures of what I hope it will look like or anything, also, I'm not above asking for help! ;)  So if any of you are super organized people...feel free to come help me, haha!  Also, once I find out what I'm having, maybe I can post pictures of nursery ideas for some overall visual goal for me to achieve!  

Also following Calista's lead...here's some follow-up questions.  Do you have a room in the house that you shove things in or that you make sure the door is closed to when there's company?  

Do you have a good system for your bills, papers, records that does Not involve an office?  Let me know what works best for you!  Because pretty soon, we won't have an office!