He'll happily pick up books he has previously read, all sorts of Astrosaurs / Captain Underpants etc but has asked if there are any other series of books now that he has finished Harry Potter / Percy Jackson. He's read most of the Roald Dahl ones, and has started on Mark Haddon's agent Z / boom books.
I'm struggling a bit at the moment as I'm wary of getting books that he can read, but isn't really mature enough to understand or appreciate properly.
Any suggestions would be very welcome so I can find something good before we go on holiday. Thanks.