Spay USA: Nationwide network of over 900 affordable sterilization programs:

http://www.spayusa.org

Humane Society of the United States: "Myths and Facts about Spaying and Neutering":

http://www.hsus.org/ace/11823

Pets 911's Spay and Neuter Page, which includes referrals to local low-cost spay and neuter programs nationwide:

http://www.pets911.com/services/spayneuter/

Prevent A Little Coalition: Spay and Neuter campaign with lots of research and spay/neuter resources:

http://www.palc.org/

Love That Cat: Information on low-cost and free spay and neuter services for cats, listed by state:

http://www.lovethatcat.com/spayneuter.html

The Dog Hause: Six Common Excuses for Not Spaying or Neutering Pets:

http://www.doghause.com/neuter04.html

Feline Rescue: List of low and no-cost spay and neuter programs in the United States and Canada. For dogs, too!

http://www.felinerescue.net/speuter/resources.htm

Happy Pets: Another great list of low-cost and free spay and neuter programs in the United States.

http://happypets.addr.com/lost_cost_or_free_spay.htm

A great personal essay about one pet owner's decision to neuter:

http://personal.cfw.com/~dtratnac/neuter.htm

The Winn Feline Foundation's Report on Early Spay and Neuter in the Cat:

http://www.winnfelinehealth.org/reports/early-neuter.html

The Pet Center: Great source of information about the actual spay and neutering procedure (Warning: includes graphic surgical photos):

http://www.thepetcenter.com/sur/ Spayandneuter.htm

The Dog Owner's Guide: "Spay or Neuter Surgery: A Prescription for Better Canine Health"

http://www.canismajor.com/dog/spayneut.html

How to Love Your Dog: "Too Many Dogs", a great page that teaches children about spaying and neutering:

http://www.kidsanddogs.bravepages.com/toomanydgs.html

NetPets article "A List of Some of the Less Than Exciting Behaviors Associated with Unneutered Male Dogs":

http://www.netpets.org/dogs/reference/ info/behave.html

Friends of Animals: Order a spay or neuter certificate online!:

http://www.friendsofanimals.org/ spaying/cover.html

How can one unspayed cat turn into over eleven million cats? Click here to find out:

http://catnet.stanford.edu/articles/ cat_overpopulation.pdf