I'm not sure they have even made new textbooks for the new JLPT yet. As N4 corresponds to the old Level 3, I think you'd be safe to study from an old Level 3 textbook.
It might be worth it to get the mock test. Most of the grammar questions are similar on the new test, but the listening is quite different. It would probably be good to study the listening a little bit before the test.
thanks for your input guys, really appreciate it. im going to go through the minna nihongo beginner II first to brush up. then may get some of those books whiterabbit has.
It depends on where you live, but in general, it's held twice a year in Asia (July and December) and once a year pretty much everywhere else (December).
Check this link for more info: http://www.jlpt.jp/e/application/overseas_list.html
It's also a great website to look into for all the JLPT goodies you desire. I was pleasantly surprised myself by their redesign.
