Buy the C&G 2391 exam success book. Well worth the £15 or so quid. It is a massive help for the written exam, with lots of tips for saving time, especially if like me you are not the best artist that ever graced the planet, and can sometimes ramble on a bit when trying to describe in detail something. This book shows you how to cut the crap and save time.
15 weeks is a good period to get to grips with GN3, learn a bit at a time, and you will have no big trouble on this course or the exams.
The biggest cause of failure is lack of revision time, so if you have 15 weeks, you stand more chance than someone who is going to take it the week after.
Cheers............Howard
telling ya, local collages are here to help... even if you have to jump skip and avoid the truth a little....
Try and do as many past exam papers as you can. Reading GN3 is one thing, but answering exam questions is another. Did mine last month, still waiting for results.
Reply to the thread, titled "just started the 2391" which is posted in Australia on Electricians Forums.