Sadly, I think your 2008 books are really out-of-date and will only serve to as you say give you lots of stuff to unlearn.
You could do worse than buy the complete package including not only books, but the other tools you'll need such as ruler, protractor, computer, map pens, kneeboard etc. You also get a bag to keep it all in so no excuses about arriving for your leeson without the necessary kit. It is a bit irritating having to lend kit to students.
On the other hand, just buy Book 1 for now, get some bookings in with your local school and see if it's really for you this time.
TOO