Nightshade is available from these online booksellers.

(You can click on the link to get yours now):

Amazon US

Barnes & Noble

Apple iBook Store (search Jonelle Patrick from iTunes)

Google Play

Kobo US

Sony Reader Store

International:

Amazon UK

Kobo Japan

Nightshade is published by InterMix, a new imprint of Penguin, and currently it's available only as an e-book, but you don’t need an eReader to read it!

Here are your options:

1. •If you already have a Kindle, Nook, Kobo, Sony Reader or other e-reader, download and start reading!
   

2. •If you have a PC, Mac, smartphone, or tablet, get the Kindle app here, the Nook app here, or the Kobo app here.(The Sony Reader will let you read on any Android device, but not on Apple devices yet. Get the Sony app here.) Then buy the Nightshade version from the website matches your app and have it sent to your chosen device.
   

3. •If you have a Google/Gmail account, Google Books on any platform is here.
   

Fallen Angel, the second book in the series, is available for pre-order and will be released by Penguin InterMix in March, 2013. Idol, the third in the series, is scheduled for August 2012.