Understandable. It's not a great place. I'll try to explain it.

4chan's format is that of a japanese imageboard. All new posts are accompanied by an uploaded image, but this is the ONLY requirement for posting (barring the occasional captcha). There are no accounts, no passwords, no emails, nothing. Everyone is anonymous. In fact, the group Anonymous was born on 4chan as sort of meta joke amongst the users, because everyone's username on 4chan is Anonymous (unless you enter a name to appear, which is frowned upon). 4chan works as a sort of hivemind that perpetuates itself through memetics. I don't just mean memes in the sense of funny pictures or sayings, but in the sense of 4chan being a microculture where the way to act and conform is dictated solely by memes or "an idea, behavior or style that spreads from person to person within a culture". From a sociological standpoint, it's fascinating and leads to great insight on the dynamics of anonymity and memes as they relate to the internet, but I digress.

The culture on 4chan is extremely volatile. There are unspoken conventions (again, transmitted through memes. Being ignorant of these conventions only gets you a "LURK MORE") that must be adhered to, and the language is bizarrely volatile and nonsensical at times. The N-word is used to great excess, but speaking as a former Anon, I can assure you that no one is actually harboring any contempt for black people. It's really said because A) it's taboo and this makes the user feel "edgy" (the userbase is mainly young high schoolers) and B) because the average user has not been exposed to racism and is relishing the chance to use a word that, for all intents and purposes, is meaningless yet still considered offensive in public. The same goes for the word "fag" which is used to a FAR greater extent than the n-word, so much so that it has lost any semblance of meaning. There have been numerous people who misunderstand this, and actually post homophobic things. These people are reviled, and are often met with opposition, sometimes with humorously ironic results.

Now you'll say, "but this doesn't change the fact that it's offensive", and you're right! But 4chan really does exist within its own little universe. The people on there aren't going out in to their daily lives as more racist individuals, quite the contrary. One of the most famous raids (website DDoSing and prank call attacks, among other annoyances) by 4chan (or Anonymous, when it wasn't it's own full blown entity) was against Hal Turner, a white supremacist radio show host.

In short, 4chan isn't the best place. It can be downright scummy, but it's not a bastion of hatred.