Click the "my account" link about your hubpages page to load your account. In the "Your Account" column you can see the link "Affiliate Settings". Input your affiliate code for Adsense and click "Set". Input your affiliate code for Amazon and click "Set".
That would like your Adsense account and Amazon account with Hubpages.
Every google ads on your hubs would now be linked to your Adsense account, hence you earn a share of any revenue earned when someone click google ads on your hubs. As with Amazon, if you add amazon capsules, such capsules are linked to your amazon account now. Any purchases to Amazon that came from your Amazon ads shown through your Amazon capsules will earn you a commission.