Who is the series aimed at? Narnia, or LotR, have one target audience for the whole series. If you enjoy one, you can read all the others. This series, you can give the first three books to a 7-8 year old, but the last ones need an older reader if only for sheer stamina, not to mention deaths and stuff. On the other hand the first three are too twee for anyone over 10 to enjoy.
I started when I was 9 or something and now I'm 15 and I enjoyed reading them as I grew up.


Spoiler Alert, click show to read: 
I didn't like the Ron does Parseltongue bit either, seemed a bit convienent. If Parseltongue can be imitated, why can it not be learned like any other language?



Spoiler Alert, click show to read: 
The other thing that bugged me throughout was the fact Harry never once decided to train or even read a spellbook on his 6 months or so of camping. I mean, your being hunted by most of the world, you always knew you would be hunted and now you have weeks to do nothing out in the countryside and what does he do? Sits and bitches like hes in the Big brother house. Even Crabbe done some training and practice and learned some stuff.