yes, read them both and don't stop there. valdimar to redwall, read them all. harp of the winds and the wizard of earthsea. sf is about suspension of disbelief, but fantasy is all about sense of wonder. that is the distinction. rather then future and past as people often mistake it to be. two different approaches to the positive value of 'the other'. either way, 'other' IS the value, and it IS positive. you need to look far beyond the familiar, to see even the familiar itself with fairness.
I liked it a lot, but a lot of other people (that also love Tolkien's fantasy) didn't. It is not the easiest read, same with certain parts in Lord of the rings. It can be a bit longwinded for a novel I guess. And... if you read it before you know the story of Lord of the rings or the Hobbit.... you might lose interest soon. Tolkiens work is best read like this: The hobbit The lord of the rings The Silmarillion
Personally, I found LTOR to be a little bit boring. The first volume is good, the second and third not so great. Couple of years ago I read 'The Children of Hurin', which I also prefer to LTOR.
The thematic elements are essentially the same - good vs evil, man vs himself, bravery vs cowardice, selflessness vs personal desire I don't think Harry Potter is for children only - I didn't read it until I was an adult and found a lot of complexity in it. It is an easier read than LOTR I know the OP is long gone, but my advice is read them both..and read them again. And again and again!
Did you know pagan LotR lovers say the same thing in regards to their spiritual beliefs? It is clearly inspired by germanic and scandinavian mythology, at least as much as christianity.
Tolkien's experience as a soldier in the first world war is also said by many to be a big influence. Yet Tolkien said what he said. I agree though - there are many influences from Scandinavian, Germanic and Anglo-Saxon sources.
It's actually why I dig it so much I doubt that without the inspiration of european medieval times and pagan mythology it would be in my favourites. But it would be a completely different book then so...