I have recently watched 'Harry Potter and the Goblet of fire', with the book very fresh in my mind. Conclusion?
IGNORE THE FILMS!
The 'Harry Potter' films are on the opposite spectrum of 'The lord of the rings' films. While the later succeeded in adding as much from the books to the films, the first ones are barely even sketches of the original story. The number 4 film in particular is a merely 25% of content and growth found in the book, and it explains really nothing.
Yeah, I would also recommend putting up with the first couple of books until you reach the 3rd and 4th...they're pretty good, although by the 4th you're already thinking the overall plot should become a bit more involved.
Reading the Terry Pratchett thread here, and on goodreads about a certain book, I realized I fall a bit weird into the Discworld fans: I didn't like 'Mort', almost at all, nor do I like 'Reaper man'...and that is funny, because I really like Death as a character.