The GuideStar database (now part of the new nonprofit organization called Candid) features the most up-to-date information on more than 2.7 million nonprofits. They get this information from the Forms 990 filed to the IRS as well as directly from the nonprofits themselves.
There are three things you should do to make sure Network For Good can successfully process and deliver your donations. First, you should claim your profile. Second, you should ensure that you're opted-in to receive donations and that your address is up-to-date so that Network For Good sends checks to the right place.
Check out GuideStar to get started or visit their help portal to get your questions answered.
Related concern: My check was sent to the wrong address.