Hi
I typed a reply yesterday and it seems to have not made it here!
Try the sticky thread on this forum - Kent test materials.
They give very useful tips!
In general bond and cgp practice books are good to build an initial foundation.
Our tutor used AE books and they were good too.
Once the basics are firmly in place most kids do the 10 min tests ...again bond, cgp, first past the post all good.
Last couple of months (we started these middle of July) it's the full test GL papers. 32 in total and we'll worth the time spent in getting the child to do them especially going over corrections.
We also did a few CGP full papers.
So far for Kent, GL have been the exam provider so their papers are a Bible.
There is a lot of material and test packs out there sometimes overwhelming but in the end you will find what suits your child.
Any questions do shout.
We are done this year but happy to stay on and help as others did

Good luck!
Mintan