IMO,
first of all, to learn any language as quickly as possible you have have a good understanding of the fundamentals of programming.
The fundamentals of progrmming are stuffs like variable, pointers (Java says phuck pointers, so you don't worry about these), statements, expressions, conditions, looping, etc.
Assuming you are well familier with the above and are trying to learn Java, first of, since Java is a fully Object Oriented Programming language it's really important to have a good understanding of object orientation. For that try to understand what Encapsulation, Inheritance, and Polymorphism mean.
And after that you have to learn how they are implemented in Java. Also remember that everything in Java is an object and every object is an instance of some class. So, you are not gona write any code outside of a class in Java.
Start with class (object), abstract class, interface and try to learn the concept of "abstraction".
Learn about the keywords.
http://download.oracle.com/javase/tutorial/java/nutsandbolts/_keywords.html there you will find the list of all the keywords, plus some reserved words (don't need to worry about reserved ones).
When you go through the keywords, also try to learn which ones are primitive data types, which ones are access level modifiers, some are even statements. ...
Oh ya, and data types. There two different data type in Java - 1. Primitive and 2. Reference
It's good to what a method signature is, it helps a lot while learning about method overriding and overloading.
Java Beans naming convention, learn and always follow it.
Now, if you think you are pretty confident with all of the above then you can start reading a SCJP book.
And if you still feel confident even after reading a SCJP book, that means you are a good Java programmer.
But that doe not really prove that you a Java expert. Your level of expertise in Java is really measured by you knowledge of all classes and interfaces in standard Java packages.
e.g. the package "java.util".
Even in the package "java.lang" there are class like Object, Class, all the wrapper-classes. ...
About the site -
I think "roseindia.com" is the worst site of all.
Try: http://download.oracle.com/javase/tutorial/ it's official. Go through the topics under
"Trails Covering the Basics".
In there, if you have any confusion or don't understand some topic then do deeper research. It's also good use some forums.
