If you run a nonprofit and haven’t sent an email yet this month thanking your advocates for their donation or their time, you will soon.

We don’t have to tell you that December is a busy month for nonprofits, as you take a look at your budgets and start planning for the new year. Part of that planning includes making sure there’s enough cash in the bank and plenty of active volunteers, and those emails can help accomplish both.

Fortunately, despite the economic downturn, Americans are keeping nonprofits on their priority list. According to the Red Cross, seven in 10 Americans plan on giving the same or more this season compared to last year.

So, to keep donors and volunteers engaged and thinking about you, here are four content tips for nonprofits:

  • Thank them. It’s a basic concept, but thanking the people who have helped you is important. Constant Contact customer the Fruitlands Museum, in Harvard, Mass., recently went beyond the standard thank you email/end-of-the-year appeal. The museum told its supporters what it was able to accomplish in 2011, thanks to their help. It also gave the people on the email list a sneak preview of the coming year, including exhibits and programs.
  • Inform them. When people donate money or time to a nonprofit, they wonder how their contribution makes an impact and if they’ve helped the organization achieve its goals. The United Way of the Bay Area created a video to let its constituents know what was accomplished in 2011 in support of its poverty initiatives: Thanks to 8,000 volunteers who completed 700 projects, and donors who contributed $60,000, the organization helped more than 250,000 residents.
  • Help them. The deCordova Sculpture Park and Museum, another Constant Contact customer, recently offered its members some stress relief during the holiday season. The museum suggested giving “the gift of deCordova”: the email included information on museum membership and items from its annual artists’ market. The best part? Subscribers could conveniently buy any of those items online, as well as at the museum.
  • Humor them. Boston’s NPR affiliate, WBUR, has had some fun with its end-of-the-year fund drive this year. The station posted a video called “A Cautionary Tale” that features its hosts and reporters doing some “alternative” fundraising — reading news on the sidewalk, selling parking spots, and singing at the subway station.

How are you engaging with supporters at the end of 2011? Tell us in the comments below.