Hello Narenra,
Thank you for the question.
The Java Tutorials link that Jaikiran has provided is probably the best place to frequently visited in regards to familiarizing yourself with the new Java SE 8 features.
In addition, you'll find it helpful to get and stay familiar with the content in the JLS:
The Java Language Specification, Java SE 8 Edition
http://docs.oracle.com/javase/specs/
-- Robert