This book came out when I was four and my sister was six. But my mum read it to us and apart from being such a young age and not really understanding most of it, i really enjoyed it.
A review from the age I am now after reading it quite a few times is:

I loved how JKR introduced the character to the world, she said on her website that she had written lots of different openings for the book, and found it hard to put everything in it yet concel so much at the same time. I think she did it very well.
I love how she gave Harry a lonley start, not a big celebrity childhood like he would have had. It sort of says that Harry always knew he was a little bit different but is shocked by how different he really is even in the wizarding world.
He shows all his talents in unecspected ways even for him and learns how much like his father he really is!