This wonderful resource has many books in Spanish. Tripulantes de la Lectura is a digital library which offers options to consult, read, explore or carry out activities with the support of reading materials on electronic devices.
You may register for the Family Summer Reading Program here. Click here to register! 
Where do I register the books read? Click here! LAST DAY to turn in reading logs (online and/or paper) is August 5th by 5 pm