Hi,
Which book to choose depends on your background, and with what aim you
wish to learn J2ME, ie. general development of MIDlets, game development ect.
Book:
Wireless
Java by Knudsen is a good book, which covers J2ME in general.
Sites:
Nokia has
alot of information about the development of MIDlets, and
you can also find alot of white papers @ IBM.
/Svend Rost