If you're an individual fundraising for a nonprofit...
Crowdfunding for a nonprofit, tax-deductible 501c3 means that as the organizer of the campaign, you should have no tax liability. This also means that you can only claim donations which you personally made with your credit card and received a donation receipt for, and not the combined donations for your entire campaign. Sorry to be so mean about that.
For more detailed information about how taxes apply to your specific situation, we recommend consulting with a tax professional, as everyone's finances are so unique.
If you're a donor...
You'll want to consult with a tax professional to make sure that your donations will qualify for a deduction on your taxes and how to receive that deduction. You'll get a receipt in your email with all of the information you'll need regarding the deductibility of each donation.
Check out this article about what to expect with your receipt and more.