You just make the content. HubPages places adsense ads in all your hubs. It even shows you where the ads will be placed when you preview the hub. If you look at some hubs you will see the ads that are placed there automatically. Amazon ads are placed by the user. Adsense ads are placed by HubPages. The only thing you need to do is to pick the HubPages ad program or adsense and make sure you they have your adsense ID code.