Pop Graphs

What are the rules for using pop culture references when writing a novel?

Can it be detailed references, or should it only be generalized? Do I need permission to use the references? What's fair game? I'm planning on writing and publishing a story and I'd love to put in a bunch of pop culture references, even if they're subtle and no one catches them.

Public Comments

1. These are called allusions. You don't need permission for them unless you are including large portions of movie/TV scripts, song lyrics, text from other books, etc. (which it doesn't sound like you are). Go right ahead!
2. Most pop culture is in the public domain, depending on how deeply you're taking your reference to it. Naming it, making up stuff about it in a general way is okay, especially with a disclaimer at the beginning of your work (if it's a book; for a story I never did that and never got in trouble-- but never wrote anything very recognizably anyway [except journalism]...) --Now I see it, it's a novel... and anyway 'subtle' is fine, no problem. A disclaimer usually says something like "any resemblance to any people, places or events living or dead [dead events?!?-- look at the small print at the start of the novel nearest you] is not intended and is purely coincidental"... Luck to you on your project...
3. It actually can be detailed references or indirect (allusion) but as a rule of thumb, not too graphic, not more than a paragraph. You want to consider whether it's important to the tone, the setting; and how it serves to make the story more realistic, easier to visialize or accept.