1) I've found quiz books to be the best. You are basically taking a fake quiz, but most explain what the answer is, and why.
2/3) Take a look on http://www.pearsonvue.org/
I used them to set up my exam. They offer vouchers for cheaper tests, and had a lot of test locations in my area.
4) I found it pretty easy. I took both tests (to get certified you need to take and pass two tests) in 1 hour and 45 minutes. They give you two hours for each tests (survey stuff included). If you spend enough time going through the books, and taking practice exams, it should not be hard.