Just sign up for both Adsense and Amazon, fill in your affiliate IDs from Adsense and Amazon into your account. That way you'll get income from 60% of all the traffic from your hubs.
Search for "make money on hubpages" in the Search box above and read all the relevant hubs. Lots of good advice from experienced hubbers. Some are making a full-time income from this. I'm not there yet but my dream is to do the same.
Start writing lots of hubs. You need to write good quality hubs but the number counts also. The more hubs you create, the more traffic you'll get and your income goes up also.