java4s

javatpoint

javanvoice

java4u

I suggest to take alook at the core java tutorial offered by the how to program in JAVA website. It was very useful for me.

You can start by following Thinking in Java . If you are interested in online resources, several free and paid courses and resources are available.
Check these very good online resources
MIT OCW
Udacity
Tutorials Point
Java T Point

The best way to learn Java or any technology for that matter is to follow any good book or tutorial. Understand the basics and working of the language/technology and try to build small programs, understand error messages (What they mean, What cause the error.). Whenever you get stuck in something, read more about it from other books and online resources, ask questions on forums. When you feel comfortable, move ahead to more complex programs and more advance topics.

Hi Bhupendra, You can read many important Java tutorials here itself on this site. http://findnerd.com/NerdDigest/JAVA