I have a sound file I want to play when a npc does its "GREETING", How do I go about doing this? Also, For dialogue, How do you make new (non quest) topics.

I'm a noob of dialogue too, but for your sound files, check out the thread "Voice Replacements" that NextMasterMind put up. It's not too far down the list atm, so it should be easy to find.

No results for Voice replacements :X
EDIT: I feel like an idiot, found it (I really should have checked post time).

That helped, But is there an easy way to just use some .wav or mp3 I have as a voice file? Do I need to put it in some folder for the CS to let me use it or something?

What do you mean? Custom voice in a custom dialogue or a custom voice in a vanilla dialogue? All voices are stored in data\sound\voice^\*plugin*\*M* or *F*\*filename.mp3*. Note that CS uses WAV-files, and the game itself uses MP3-files.

Isn't it mp3 files for the sound and wav files for the lip-synch?

Yes, with that correction.