I took mine through Target Sports in Gormley, and I was satisfied with the level of professionalism. I think they have links to upcoming courses on their website. I've taken civi and mil courses, and imo, it never hurts to take the full course (if even as a refresher), than to challenge the exam. Also, imho, as with pretty much any subject, one can learn it from a book, but an instructor with that background will always provide additional information that isn't in the books. Good luck! :-)