Do a search for each of these on Google keyword planner keeping the country USA. I did the first one for you and the result is around 18,100 per month which is huge. Obviously, the competition is high too so this is not recommended for a newbie. Keep on digging. There are millions of products on Amazon. Find something that is less competitive. It can be literally anything from Knife to generators.
If you are a music lover, it would be a good idea to promote it over books and even other products. All you need to do is listen to clips of a full album within a short period, say 10 minutes, get a good feel of it without you purchasing it and do a short review. If there is another niche you are passionate about, make sure you get a unique discovery about it. Of course, there are hundreds of thousands of reviews about these products all over the web but you need to make yours more unique to attract people to your site.
Once you've protected your prospecting pool, maximize your affiliate program by working with the best and leaving the rest. As the old 80/20 adage implies, most of your revenue will come from a very small percentage of your affiliates. Because it can be time-consuming to manage a larger affiliate network, consider selecting only a few companies initially, and interview them before signing them on. Affiliates are an extension of your sales force and represent your online brand, so choose partners carefully.