NEW YORK — More than 20 years ago, Donna and Robert Considine decided they wanted to focus their charitable giving on something that was meaningful to both of them.

She was a fan of entertainer Danny Thomas and became interested in the St. Jude Children's Research Hospital, which he helped found in Memphis, Tenn. The hospital, which provides free care for children with catastrophic illnesses, also resonated with her husband, she said, because his mother had considered St. Jude to be her patron saint.

At first the couple from Niantic, Conn., sent checks in response to the hospital's Christmas appeals, but then they started making a monthly donation "and we just never stopped."

As the holidays approach, Americans are being bombarded with mail and phone solicitations seeking help for needy families as well as for groups devoted to animal welfare, the arts, the environment, education, religious causes or community issues.

Many people aren't sure about the best way to choose among the thousands of charitable and nonprofit organizations.

Philanthropy experts say people should follow their hearts in giving. They also say targeted giving like that of the Considines can help charitable groups because it provides a predictable stream of income so they can plan long-term projects.

"Unlike the stock market, you really shouldn't be diversifying your giving," said Sandra Miniutti, spokeswoman for Charity Navigator, a nonprofit group based in Mahwah, N.J., that evaluates philanthropic groups. "It's best if you stick with a charity over time, make a commitment for the long haul."

Donors also should check out the charitable and nonprofit groups they want to support to make sure they're spending their money wisely, she added.

Sites like www.charitynav igator.org, www.give.org and www.guidestar.org provide background information and ratings on thousands of charities. Another option is to go to a charity's Web site and check its IRS Form 990, which should include a breakdown of its spending, Miniutti said.

Miniutti said well-run philanthropic groups generally spend at least 75 percent of their budgets on program activities, with the balance going to operating expenses and fundraising.

This year there's concern that there may be fewer holiday donations because Americans already have given so generously to aid the victims of natural disasters.

The American Red Cross alone has received more than $1.6 billion in gifts and pledges to help survivors of hurricanes Katrina, Rita and Wilma; $5.4 million for those left homeless by the earthquake in Pakistan; and $567 million for relief efforts in the South Asian nations hit by the 2004 tsunami, according to Red Cross spokeswoman Kara Bunte. And donations for those disasters are still coming in, in part "because there's been such obvious need" in the disaster-hit areas, she said.

Still, there are many other deserving causes that rely heavily on holiday giving, and the potential for "donor fatigue" means a family's contributions this year may have a bigger impact than previous years.

That's the hope of Helen Patrikis, an account supervisor with a New York public relations firm.

Patrikis said the many disasters in the past year "really make you stop and think about your own personal situation ... and about what you can do to help others."

So for the holidays, she and her husband, Nick, decided not only to donate to a half-dozen charities — including the National Parkinson Foundation, the Sundance Institute and the Conservation Fund — but also to ask family members to make contributions instead of giving them gifts.

"It just feels right this year," Patrikis said.

Actress Marlo Thomas, who has continued fundraising activities for St. Jude's since her father's death in 1991, said donations make up more than two-thirds of its budget. The rest comes from grants and estates.

She's again heading up the hospital's "Thanks & Giving" campaign, which urges Americans to give thanks for the children in their lives who are healthy and to give to those who are not.