There are drop shipping companies also known as wholesale supplier directories like Worldwide Brands, SaleHoo or WholesaleCentral. They provide access to hundreds of suppliers with around a million range of products. Usually, such directories ask for a monthly fee or a one-time lifetime fee.
It can be a good way for independent dropshipping shops with own websites. Especially if you are making a large purchase and get a discount. But while making low orders you may not get a discount big enough to be profitable on Amazon. Because Amazon drop shipping sellers have to have very competitive by price offer.
The easiest way is to buy products like for yourself at retail shops like Walmart, Target, or HomeDepot online. Then fill delivery info as for your customer, control the delivery and get profit finally. To automate such processes for Amazon drop shipping sellers we created TrackMyOrders system. To know more about supported retail and wholesale suppliers, searching for products, publishing listing, tracking, repricing, and more other features visit Amazon Products Scout Module Page.