If you want a layman approach then this Youtube video about where gold comes from is pretty good. You can skip most of the first half about the culture of gold. The second half of the video is the creation part.

If you want a technical approach then you want to talk about Rapid Neutron Capture and GRB. You'll find that kind of talk here. Warning: When you start digging deep into scientific explanations you discover that there's more we don't know. As the article ends with the idea that our current working theory of r-process doesn't happen often enough to explain how much gold we have so there's likely at least one other way gold is created in the universe. Welcome to cutting edge science!