"Just because someone shares something on Facebook, doesn't mean they've checked out the group," Borochoff said.
And while taxes might not be at the forefront of your mind right now, remember that charitable donations to qualified nonprofit groups generally are tax-deductible if you itemize your return instead of taking the standard deduction, so keep your receipts.
Additionally, crowdfunding sites have campaigns going on. Among them is GlobalGiving.org, which is hoping to raise $2 million exclusively for emergency disaster relief and long-term recovery efforts. GoFundMe.com has an area on its website dedicated to fundraising efforts for Harvey victims, as does YouCaring.com.
Among the well-known groups taking donations specifically for victims of Harvey:
1. The American Red Cross, which has shelters open and is getting supplies to victims, is accepting donations on its website via a dedicated link. Donors also can call 1-800-RED-CROSS or text "Harvey" to 90999 to make contributions. Alternatively, some companies are collecting donations for the Red Cross relief effort on their websites. Among them are Amazon and Whole Foods, which will match cash donations (up to $1 million total).
2. The Salvation Army, which says it has disaster teams from across the country mobilizing to help Harvey victims and will support long-term recovery efforts, is also taking donations on its website. Or, you can call 1-800-SAL-ARMY or text "STORM" to 51555.
3. Catholic Charities says donations for Harvey victims will go toward food, clothing, shelter and a network of support services for those dealing with the aftermath of the storm. Contributions can be made via its website or by calling 713-874-6654. You also can text "CCUSADISASTER" to 71777.