If I live in NY and I am starting a Online Business, What do I need to do in order for my business to be legit

I am starting up an Online Business where I will be selling products that I have purchased from a Wholesaler and selling them for a Suggested Retail Price. I want to make sure I am safe all the way around, How do I register my Online Business if I live in Brooklyn, NY? Do I also need to Register as a Reseller? Do I need my Sales Tax ID as well? This is the first time for me, I am new to this whole thing, I want to be sure I am Legit 100%, What Legal Documents do I need in order to be a Legit Business? and Where can I find these Forms to fill out?
Any help would be highly appreciated...
Thanks for the help

You will need a state sales tax ID. If you sell to anyone in NY, you are expected to collect sales tax, and report it quarterly.You will also need a business ITIN. (income tax ID number). Wholesalers will not sell anything to you without one. Tax is not "forgiven", it just moves from the wholesalers responsibility to you as the retailer.

Honestly, I have to question your business model.

Why would anyone pay full retail from you (an unknown) instead of just buying it retail in a store, where they would have a warranty, ease of return or more. Also, is the product you are selling so scarce that you can demand full MSRP. There are very very few things that sell at full retail on line. What about cost of inventory, marketing, credit card processing, shipping, returns, bad debts..Have you built all of that into your model?

I hope you are successful.

Good Luck