...book/film. Is seeing the 4th movie this weekend a problem? Will I be confused and missing details/information from previous books/movies or will I be ok as this film is self-explanatory in itself?

[Lightning]

You should generally be able to follow.

JKR's plot is actually very linear. You will miss out on a fair bit of "Easter Eggs" that may be dropped in the film and/or scrutinized obsessively by fans, but you shouldn't be too bad.

I'd recommend reading the book of any movie based on a book, though -- series in particular.

It is most definitely NOT self-explanitory. Even as an extension of the other movies, the 4th movie just doesn't fit - the plot seems to jump around and the characters are not well-introduced - the entire movie just doesn't make sense. It is still visually appealing, however, even if you have no background with the Harry Potter series.

There is just too much content in the 4th book to be compressed into a 3-hour movie. If you've read the books, however, you'll love it.

The 4th book is very long, something like 700 pages, so the movie condenses a lot of what happens in the book. having read the book, I think I filled in a lot of the details, but some parts would be confusing to someone who doesn't know the story.

at least watch the other movies so you get some of the back story