Now that I have a 7-year-old little brother who can read these things, he's now a Pokémon fan too. Well, somewhat - not "fans" like us, but "fans" in the sense that he sometimes gets crazy about it (probably) without knowing what he's doing.
But it's a blast to the past for me as well, because I remember having those books in the library myself when I was only 7 or 8. And these are from the times of Johto, not the Diamond and Pearl books that exist now.
What really caught me about these books is how crappy the artwork is - it looked like somebody tried to trace Sugimori's artwork in MS Paint, and then superimpose it on a radially striped background like you sometimes see in comic books. They're not even actually pictures of what happens in the book. Others are just scan-prints of the anime, and do show what is happening.