Oh! Due to my agitation I nearly forgot: thank you Eisblume for the Wikipedia-link with the name explanations. That's really a lot of information.
And regarding Harry Potter (yes, Harry Potter is great literature): the difficulties are probably the "technical terms". All this "cauldron" and "broom" stuff. Once you get used to it it's not too (*) difficult. And it's definitely worth the effort, the original english version is orders of magniude better than the translation (at least than the german translation). I had this problems when I started to read Pratchett's Discworld novels in english, I was simply not used to this kind of vocabulary.
(edit: "too" with two "o"s? Yes. Well, my english ist obviously still not too good, despite the english discworld novels)