Sure here is the basic overview:
http://www.apple.com/support/products/iphone.html
Here is the info for any iPhone pre-ordered or purchased after Oct.14:
http://store.apple.com/us/product/S4575
How to get AppleCare+
AppleCare+ must be purchased together with your new iPhone. To buy it, add it to your shopping cart during the checkout process when you purchase your new iPhone.
Note: Through November 14, AppleCare+ can be purchased by customers who:
Pre-ordered iPhone 4 (8GB) or iPhone 4S
Purchased an iPhone (any model) on or after October 14, 2011 (proof of purchase date may be required)
Contact us at 1-800-275-2273 to purchase AppleCare+.
Dave