Hi Romcab!
I don't know much about J2ME/JME myself. I only got as far as accessing the phonebook and getting all the contact info/numbers and creating high-level GUI. We can't program exactly the way we program desktop applications in J2ME, ther are several restrictions like how efficiently you handle Strings and floating-point operations. Please allow me to cite some of the resources I have found useful during my study.
http://www.j2meforums.com/forum/
http://today.java.net/pub/a/today/2005/02/09/j2me1.html?page=1
http://today.java.net/pub/a/today/2005/05/03/midletUI.html
http://java.sun.com/javame/reference/apis.jsp
http://supremej2me.bambalam.se/
http://developers.sun.com/techtopics/mobility/midp/articles/wtoolkit/
http://developers.sun.com/techtopics/mobility/midp/articles/tutorial2/
You may want to start with Sun Java Wireless Toolkit first. Then, once you're comfortable with how to compile and the structure of a MIDlet jar, try Netbeans IDE and download the Mobility Pack.
If you're into gaming, there's a free e-book written by Jason Lam that you can download here.
HTH!

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