For freelance writers and other self-employed people, the end of the year isn’t just about office parties and getting the Christmas gifts bought and wrapped. It’s also time to take care of some major business housekeeping before the calendar flips.

Here’s what’s on my to-do list:

Send cards to editors. Some freelancers send gifts as small tokens of their appreciation for the work that came their way during the year. I think a card to the editors you worked with this year with a heart-felt expression of thanks works just as well. And if you’re trying to go green in your business, consider virtual greeting as an option.

Take care of invoices. Mail or email any outstanding invoices before Dec. 31. Sometimes if I turn in a piece a day or two before the end of a month but the editor hasn’t had time to look it over yet, I’ll ask if it’s OK with them for me to send an invoice anyway, so I can put it on my books for that month. Nobody’s ever said no. If for tax purposes you want to defer income to next year, wait and send invoices in January 2009 for jobs you finished late in the month. Resend any overdue invoices.

File expenses. Do not wait until April 15 rolls around to sort through the expense receipts. Whether you use a spreadsheet, QuickBooks or a plain old pencil and paper, organize your business expenses for the year while they’re still fresh in your mind.

Make business-related purchases. If you’ve had our eye on an iPod Touch, Blackberry -  or like me a digital voice recorder – take advantage of holiday sales and purchase electronics and other office equipment now.

Create a business plan for 2009. This could be as simple as writing a list of things you want to accomplish during the  coming year. Or it could be a more elaborate review of where your business came from this year, how you want that to change in the next 12 months and how you’re going to accomplish those changes. If you’re not sure where to begin, check out freelance writer Heather Boerner’s blog, Serenity for the Self Employed, where she’s currently running a 30-day business plan challenge.

Update your resume and social network profiles. Once you’ve created a plan for how you want your writing business to run next year, redo your Facebook and LinkedIn profiles and your resume to fit the new you.

Update your blog – or start one. Last year, I spent the better part of New Year’s Eve day and New Year’s Day setting up this blog. Boring, yes, but it was time well spent, and it was easy to keep one eye on the college bowl games while doing it.

Clean your office. If you’ve got a lull in assignments between Christmas and New Year take advantage of the down time by giving your work space a once over. Nothing like starting the New Year off with a clean desk, papers filed, magazines organized and supplies sorted.

Send a letter (or 2 or 3) of introduction. Odds are some editors will be working through the holidays. Use the opportunity to catch a new-to-you editor when everyone else is on vacation and introduce yourself or submit a couple queries. I sent a LOI to an editor at an about-to-be-launched news service a week ago and got a note from her yesterday with a request for some story ideas.

Give thanks. In a year when hundreds of not thousands of working writers have lost their jobs, be grateful that you’re self employed and not at the mercy of  single employer. Working for yourself isn’t always easy but right now it sure beats the alternatives.