Welcome back! Hopefully you've been following along and signed up for an Amazon Seller account following my three part instructions found here, here and here. If not, please make sure you go back and follow the steps before continuing with this post. The app is useless without an Amazon Seller account.
Now that you have an Amazon Seller account it's time to do some research. There are many different ways to research items to sell on Amazon. One of the easiest is using a smartphone to scan items with a barcode. There are a number of different apps (Scoutify, ScanPower, ProfitBandit) that offer services to look up the information about a particular item on Amazon using a barcode scan. Each of the above come with a monthly fee (some on the high side). Amazon came out with their own smartphone app in March 2014 and it's FREE which is perfect for sellers just starting out.