Whether or not nonprofit organizations can truly gain value from a Twitter presence has been the subject of debate. With direct fundraising via Twitter not yet commonplace, some argue that measuring Return on Investment (ROI) is difficult. However, more and more examples of nonprofits leveraging a strong Twitter presence to publicize their cause and effectively engage their target audience emerge every day.
A nonprofit organization can begin to build an effective Twitter presence in several basic steps.
Keep in mind that Twitter is a two-way communication street. Strive to give your audience a reason to stay connected, and provide opportunities for direct action whenever possible—usually in the form of a hyperlink that takes the person to a webpage where they can carry out that action.
1. Have something to say
As a nonprofit organization, your mission begs to be spoken
• Use your mission statement as a guiding point in determining the type of messages you wish to communicate with your audience/Twitter followers
• Use the “Bio” field on your Twitter profile to provide a brief description of your mission

• Tweet specific examples of your organization fulfilling its mission

• Use breaking news related to your cause to motivate your audience/followers to get involved, providing specific calls to action whenever possible
The devastating 7.0 magnitude earthquake that struck Haiti late Tuesday afternoon spurred The American Red Cross, @RedCross, to utilize its Twitter account to promote donation appeals, as well as inform the public through frequent updates on the progress of fundraising and relief efforts.

2. Say it succinctly and regularly
Allow the nature of Twitter to work in your favor
• Commit to tweeting regularly – although there is probably no “magic number,” aim to tweet several times per day
• Twitter will help you with the succinct part- you’re limited to 140 characters per tweet
• With its purpose in mind- is it to educate your audience, make an appeal for donations, or share a moving success story? – try to craft your tweet in the most fitting words
3. Make your presence known
Be personal and professional
• Create a professional looking Twitter profile background
• Become familiar with the “Twitterverse” of your space – locate, follow and retweet relevant messages from people and organizations relevant to your organization/cause, including advocates, consultants¸ media outlets, bloggers and legislators
• Get listed under Nonprofits in free directories including Tworgs, Twellow and WEFollow
• Be authentic and let the personalities of your staff and culture of your organization shine through in your tweets

Recommended Resources
Articles:
How to Show Your Soul and Engage with Twitter (Tips for Brands and Non-Profit Organizations)
Tweet, Tweet, Ka-Ching: Twitter is Changing the Way Nonprofits Make the Ask
How Frozen Peas Started a Movement
Blogs:
Beth’s Blog: How Nonprofit Organizations Can Use Social Media to Power Social Networks for Change
Organizations:
NTEN: The Nonprofit Technology Network
NetSquared: An initiative of TechSoupGlobal.org
Tools:
act.ly: allows you to easily promote petitions, retweets and events to the Twitterverse
twitpay: a simple way to get donations on Twitter. All you need is a Twitter and PayPal account.
Niki Konkoly — A lifelong writer who created "The Weekly Geekly" long before the Onion existed, Niki provides web updates and Google AdWords account management services. Her hobbies include skiing, traveling, and hiking. She can be found in the Twitterverse at @nikikonkoly

Happy tweeting!