Don't .
Also don't try to sell by dropshipping. You will have thousands of competitors and if anything goes wrong it will be you that gets blamed (negative feedback, trashed DSRs) and not the supplier.
Sell what you know: know what you sell.
Never sell anything you don't have in hand, package it carefully and ship it promptly.
That your supplier is not able to give you clear instructions on how to use his catalogue is a pretty good indication that he is horrible at customer service.
