3. Browse the forums related to said book/film.

Seriously, you'd be pretty silly to do this, especially because there are a lot of idiots out there who don't know the meaning of the spoiler. It's no use facepalming yourself because you accidentally read a thread's title which goes along the lines of "ZOMGWTFBBQ [character] DIES IN CHAPTER [number] WAAAH". It's your fault, so suck it up and learn from it. Unless you want to be spoiled, of course.

Forums are made mainly for discussing entire books/films; for example, I haven't encountered any forum that caters to only one chapter (and no, I'm not talking about series of books, entire books do not count as chapters). When you enter a forum, don't expect others to hide everything or pamper you; most are assuming you've already read the book or seen the film, they don't know you're "halfway there" or you have "one more chapter to go" (and they don't care either).

Note: browsing forums can be useful when planning to read potentially controversial books or see controversial films. To give an example, I was planning to read Sade's "120 Days Of Sodom", simply because I'd heard of its notoriety. However, I wanted to have an idea of what I was getting myself into, so I visited some forums where readers (politely) discussed it, and found out some things about it. Therefore, forums can be good when you're trying to find out what isn't written in most reviews (in-depth things). Don't try to find out more than that, though, since it will *drum roll* ruin your reading experience, of course.