Amazon product upload

Need to know how Amazon US Pro Seller accounts work and how to upload csv files to an account. I need someone to upload various files from Chinavasion and National Dropshippers (and maybe more later). There are thousands of items of various general products (not books or music though) on the csv files. I need to convert the prices (to make it easy, we'll just say 50% higher). Then I have to put them in the proper categories that Amazon needs and the "optional ones" too (i.e. images). Some of the issues (especially with the Chinvasion) is that ASINs don't match.