Question: I have a decent programming practice with languages such as ASM, C, C++, PHP, JS, even ActionScript for Flash, and now I feel a strong need to learn Java. But I prefer to explore new languages in practise, and it seems like, if you want to write something worthwile in Java, you have to know this, and this, and that, and so on... So, I don't event know where to start at.  

**Edit**: I'll try to concretize. As far as I'm concerned (at my point of view) Java is all about technologies and frameworks, lots of words: JSP, JSF, Spring, Hibernate, Swing, etc. I would like to move to a new platform corporate website (CRM-like system) I'm in charge of. Choise fell on Java, but I can't figure out how to implement it. What technologies, frameworks, other resources I'd have to use for my purposes to shorten the "study part" as much as possible, and begin the "developing part" as soon as possible.

Answer: 
Try [the official *Java Tutorials*](http://download.oracle.com/javase/tutorial/). They are actually quite good.
Most of the languages you have learned are Imperative programming languages. Make sure you divide your task into two; learning object oriented thinking and learning the Java language.

I've heard good things about [Object Oriented software Construction, 2nd Edition](http://docs.eiffel.com/book/method/object-oriented-software-construction-2nd-edition); but, as a disclaimer, I read "Learning Java" from O'Reilly. I'm not sure if the O'Reilly resource would be as good for you, as I didn't have to worry about the Object-Oriented aspects when I approached Java.

Good luck.