What would be the best step to learn Java thyself?
The SitePoint forums no longer have a Java forum.
Even though its focus is on using Java for the web and it is very old, taking a look at the Java Servlets and JSP resources sticky might be a help.
You can definitely learn online but books aren’t so bad.
This one seems good for online.
http://www.javavideotutes.com/
for books, just get the book that has the highest rating in Java.
I have to say Java is Easy to Learn but Hard to Master. Just learning Java itself will not get you very far in career. Here are the top Java frameworks that the industry are looking for.
Spring Framework
Spring MVC
Spring Web Service
Hibernate / JPA
Hadoop
A few others (at least at my company) that you may want to consider:
GWT (Google Web Toolkit)
Sencha GXT
SmartGWT
These three frameworks are quite powerful as well and are great for building web apps. They can be cumbersome for a small project, but for medium to large they excel. We use JPA heavily combined with GWT/Sencha GXT currently.
You should start from the basic and after that intermediate programming. I prefer oracle java. You can see documentation here. http://docs.oracle.com/javase/tutorial/
To me, I wouldn’t touch GWT at all. Their philosophy is “You don’t have to learn JavaScript to code in JavaScript”. Really? I’d never join a team where developers fear learning a programming language. Just my opinion and I’m sure some will disagree with me.