The warranty on all NOOK devices is 1 year.
This covers failures due to manufacturing defect.
It does not cover accidental damage (you dropped it).
At time of purchase you can buy an extended warranty that extends coverage to 2 years from date of purchase and also covers accidental damage.
There are also third party warranty companies that will cover a NOOK device such as SquareTrade which offers a 3 year warranty with accidental damage insurance.