The best suggestion for tools is to download Sun's Wireless Toolkit and play with it for a bit. (Personally, I use my regular
IDE for coding and then integrate through WTK to do my testing.) It should accomplish the basic tasks you'll need for learning
Java ME.
The only outside source I used for my prep was Beginning J2ME (3ed) from Apress - I had a copy of Whizlab's SCMAD simulator, but ended up finding it something of a wash while preparing for the exam. My flashcards, targeted to the areas that I felt weak on, seemed to do better by me.
Good luck!