Vegetarian/Veganism
http://www.vrg.org -A nice site with loads of info about a veg*n diet for everyone[adults, kids, teens, ect.].
http://www.goveg.com - Honestly, this site helped me a lot when I first became vegetarian. It has great info about animals, foods, and health. I strongly suggest for you to visit it.
http://www.vegetarian.tips.com -It has tips! xD
http://www.vegweb.com- The social recipe-sharing vegetarian site.
Animal Testing
http://www.altweb.jhsph.edu -So much info. x.x; Don't let the wierd URL fool you!
http://www.aavs.org/index.php -It has helpful info!
Fur, Leather, Wool, and Silk
http://www.furkills.org -Gruesome info about the horrors of fur.
http://www.furisdead.com - Just another anti-fur PETA campaign
http://www.cowsarecool.com -Probably the best site name ever! xD Oh, and good info too. Lol. ^^
Animals in Entertainment
Currently we have no sites that are just for Animals in Entertainment. Check the Animal Rights websites since they probably have some things on that.
Sanctuaries*
http://www.bigcatrescue.org -I love them!
It has great facts on cats and the cruelty they endure.Animal Rights in General
http://www.Peta.org -I know they're not loved by all and I'm not 100% for them myself. However, they have great information about all kinds of cruelty.
http://www.peta2.com- Here's PETA's teen site.
http://www.freedomforanimals.org - Good site and good info.
http://www.animalaid.org.uk - An awesome UK-Based AR organization, They also send out free Action packs
(To UK only 
) But you can convince them to send a pack or too...(Thats what I did )More Coming Soon
*They must be non-profit, don't breed/sell/buy/kill their animals, don't operate like a zoo, make sure their animals are healthy, and treat them with love and kindness.
Sorry it's short.
Be free to send me sites via message so I could check them out. Peace! 