I've discovered an additional and important one. It is at www.therainforestsite.com. Go there and click (it's free) to help save the rainforest and its animals.
The others are: (to help shelter animals) www.theanimalrescuesite.com and www.freekibble.com (which donates pet food to shelter dogs and cats).
I've added these three websites to my "favorites" and click on them every day. Free Kibble has interesting little animal quiz questions that are fun.