Thanks very much for the replies baboon and ogy.
I've got the National Trail Guide, which divides it to 9 stages (days), and seems to have really good directions and maps. From your comments, sounds like I shouldn't go too far wrong, but my mapreading and compass skills are more than a bit rusty, and I may be on my own for some of the stages - sounds like you're both suggesting I do a bit on these before I go....
A friend mentioned GPS systems - any thoughts as to whether they're useful, necessary and how much they'd be?