The contest, sponsored by Amazon, Createspace, Penguin Group USA and Publishers Weekly, offers two grand prizes of a full publishing contract with Penguin, with a $15,000 payment to the winners (one each for general fiction and young adult fiction).
There are also prizes for finalists, quarter-finalists and second round finalists. Winners will be announced on June 16th. To my knowledge, all entrants receive a code to order a free proof copy of their novel from Createspace.
To be eligible to enter, you must be at least 13 years old and fully own the rights to a novel of between 50,000 and 150,000 words (i.e. it must not have been subject to a publishing deal before, but can already be self-published).
Entry is straightforward: in the first instance you will need to register with Createspace; you will then need to submit a pitch of less than 300 words, an excerpt of between 3,000 and 5,000 words and the complete version of your manuscript. The entry period runs from 23rd January to 5th February, or until 5,000 entries are received for your category (young adult fiction or general fiction).
Further details on the entry requirements and official rules can be found on the contest website: http://www.amazon.com/abna.