As charities gear up for the busy year-end fund-raising season, many groups are getting better at raising substantial sums online.

What online approaches have been the most successful for nonprofit groups? What are the best ways to use social-media tools to raise money and promote a good cause? How can nonprofits make their voices heard above many others online?

Join us on Tuesday, September 21, at noon U.S. Eastern time for a live online discussion about these and other questions related to year-end fund-raising efforts online.

The Guests:

Veronica Brandon Miller is executive director of ShelterBox USA, an international-relief organization that provides tents and other supplies to victims of disasters. Since joining ShelterBox in October 2009, Ms. Miller has increased the organization's fund-raising totals from $800,000 last year to more than $10-million this year, largely through the use of social-media tools.

Jeff Patrick is the founder of Common Knowledge, a San Francisco online fund-raising consulting business. He has worked with dozens of charities to use e-mail, social-networking sites, and other tools to raise money.