Here's a link to Apple's Warranty for ipods: http://www.apple.com/legal/warranty/ipodisight.html
If it's a manufactors defect, you should be ok. If it was due to mishandling or dropping the unit, it's generally not covered.
If you purchased the AppleCare extended support option, your warrenty AND phone support is extended for a full 2 years on the iPod.
For more information on Applecare: http://www.apple.com/support/products/applecareipod.html
You can add applecare at anytime during the inital 12 months that you purchased the product. After the initial 12 months, you would no longer be eligible to purchase it.