As for me I attacked it the simplest way possible. I've started out a page and then uploaded photos of the products I'm selling. For me, the best investment is on images. Since people are more visual. But of course, I have invested in Facebook ads as well to immediately get everything in the game. A good friend of mine sent over a case study on how to target the right audience for my ads on Facebook. This might help you out as well.
Of course you can sell your products from your Facebook. But i think that you can not manage payment there, so the best way to post the product image with a few description and at the end put your site's product URL. Through this you gets traffic, conversation and payment easily.