@Xortberg: I think it's pretty simple.
First making the "credit list". You take note of every material made by anyone that's not you (this hypothetical script made by Tsukihime? you put Tsukihime on your credit list). Remember of course that the RPG Maker and the RTP are things you didn't make, so put Enterbrain in your credit list.
Also when making this credit list, care for order. Sepparate names between areas, like Graphics, Coding/Scripting, Audio, etc etc. And why not, alphabetical order FTW!
Then, defining the places where your credits will be shown. Practically, the typical place for that is a "credit roll". It can appear on the menu (New, Load, Credits, Exit), at the opening sequence, or at the ending sequence.
Also remember, the "credit roll" doesn't needs to be rolling. You can make a scenario, for example, and distribute the names inside the scenario, maybe as graffiti. Be creative!
Good thing to do is, after adding something to your game, you write the author's name somewhere (like a TXT file). After all, taking note of the author takes much less time than doing the actual resource.
I hope this helps you, salut,
Orochii Zouveleki