Thanks to the internet, it's easy to find comic book distributors these days — you can simply start out with a Google search for "comic book distributor." From there, you'll have to browse the results to find distributors that sell the comics you want to stock. Some examples of comic book distributors are Diamond Comics and UCS Comic Distributors. You will need to sign up for an account as a retailer to start buying wholesale comics from the distributor(s) you choose. Both of the previous links go straight to that distributor's retailer page, but you should browse the rest of their sites as well to learn more about them.