Nathan,
As an absolute minimum you'll require a "pass" from all of the CPL Aviation Knowledge Exams, and, an FI rating from a recognised training establishment. As a PPL holder you can then instruct... but not for remuneration! Should you wish to be "paid" for providing flying-instruction, you'll need to obtain a minimum standard of that of a CPL.
If you're serious about flying, the next logical step (from a PPL) would be a "distance learning course" for the issue of a (frozen) ATPL. You'd require a minimum of 150 (P1) hours to enter into such a scheme.
It's an expensive hobby isn't it?
LASORS will provide you with all of the neccessary details.
All the best
TCF