Here is the link
http://www.squaretrade.com/pages/
They don't have an option for ebook readers (or Kindle) but when I contacted them, they told me to register it as Drive/Storage (under Computer-Other). Others have been told to register it as a PDA; however, I noticed the ADH is more for a PDA. Either way, you should contact them immediately afterwards and have them update their records to reflect it is a Kindle.
Also they have coupon codes if you search around.
Its a 3 year warranty from the date of purchase. Amazon's 1 year warranty does not cover accidents, square trade does IF you purchase ADH within 30 days of purchase.