How much does it cost to put my dog to sleep and where do i go i live in south jersey?

You would have to ask the individual service providers for their pricing and if you want to cremate your pet or just do communal burial or anything like that. If finances are a concern you can look into low cost clinics and your local shelters and aspca are often a good place to start looking.
www.njspca.org
http://libertyhumane.org/home.php www.pfaonline.org
www.yext.com