Ask HN: Advice on how to start an online store?

My business partner and I are working on an idea of building an online store to sell computer components, accessories, and systems. I've looked at shopify.com to setup the store. The problem is that neither of us have worked in the industry, so we don't have any experience building relationships with companies to sell their products. We understand that there are fulfillment centers and other businesses we could partner with to limit the amount of inventory we'd have to maintain ourselves. We're looking at selling components like computer cases, motherboards, CPUs, RAM, accessories like wireless keyboards, barebones systems, and possibly other gadgets like media players. Does anyone have any advice on how we can build relationships to be able to sell these types of products? Who can we work with to sell products while maintaining as small an inventory as possible?