My "office" currently isn't organized because we just moved and, well, NOTHING is organized.
However, I do have a few hints because, usually I am very organized ...
~ Most of what is filed is never needed again. At the beginning of the year I designate a tray or drawer for papers that need to be kept. Then when I have a piece of paper that needs to be kept, I just stick it in the drawer - not in a file, just the drawer. Yes, this creates a stack of papers but remember, most of those papers you'll never look at again. To find a paper that you do need, it is somewhere in that stack in roughly chronological order. If you can't bring yourself to do this, make a file for a month. At the end of the month, make a new file. That way you can look through files one month at a time.
~ You probably have a lot of tax paperwork you need to keep, create a separate file or drawer for that stuff. Label the drawer so you can keep it all straight.
~ I don't put my tax papers (and all supporting documents) in a file folder. I slip them in a manilla folder, mark the envelop with the year, then toss the envelop in a box for "taxes". Periodically you'll run out of room in this box. At that point you'll remove the oldest folder - one that is at least 7 years in the past - and recycle it (through a shredding service, if available).
Okay, that covers the annual stuff. Here are some hints for the day-to-day stuff:
~ Avoid paper. Google calendar and e-mail is awesome. Most of my bills are paperless. I pay all bills on-line either directly at the vendor site or through my bank's free bill pay service.
~ We have a PO Box. I don't collect the mail daily. I try to collect it weekly (hubby likes to get it more frequently which throws off my system). The PO Box is only for financial stuff, bills and important papers. Everything is safe there. I pick it up once a week and deal with it all at once. If this wouldn't work for you, consider putting a basket by your front door. Pick up the mail from the street, glance through it to make sure nothing important has arrived (a check, for instance), then toss the mail in the basket. Clean out the basket once a week.
~ I keep an Excel spreadsheet of the bills I need to pay monthly, periodically and annually (all on one spreadsheet). At the top of this spreadsheet I keep track of all our income; putting projected income for the month plus whether or not that money has been paid. If you live off of savings for part of the year, you might want to put your savings account balance in this area, too. Below the income section I list all our bills. For the due date I use the closest week or 5th day (due dates are 1st, 5th, 10th, 15th etc). This just gives me a general idea when they are due and I don't have to keep managing due dates since they change slightly month to month. I list the amount I've budgetted for that item then in a separate column the amount actually due and in another column the amount I actually paid. Depending on the bill, I might also list the interest rate and balance due (like for a medical bill). Speaking of medical bills, I rotate regular medical and dental appointments or prescription refills on this spreadsheet, too. Yes, I also have a column for comments. If it would be easier for you, I used to do all this long-hand on a piece of paper using accounting ledger paper.
~ While paying bills, I update the check register on my Quicken and the Excel spreadsheet at the same time. Yes, the Quicken software is wonderful. I don't even keep a physical check register anymore. I just check my balance on-line then export the data from my bank to the Quicken software and reconcile electronically. Again, this eliminates paper to organize.