Sea Urchin, bluebirrrd, Maiakity, JulieBeth, Battah and All,
I commend you, each and all, for starting out thinking of the business end and not just the fun of making jewelry, which is what I did for 4 years before opening my etsy shop. Thought it would be a fun way to keep D-I-Ls, Granddaughters and friends supplied with gifts. Here in Oregon there is no sales tax, so I was off the hook there, and using my personal name rather than a dba means no filing with the state.
Etsy offers lots of help guides for setting up your store and blogs such as this one:
https://www.etsy.com/blog/en/2013/the-seller-handbook-archive/?ref=help_seller_handbook#taxes Etsy forums offer help and advice also, some of it very good.
As I previously mentioned to Sea Urchin and Bluebirrrd via PMs, I don't recommend my paper bag method, although I do keep my business paper bag and personal paper bag separate. And clearly marked! So I am publicly admitting I am not really qualified to give advice in this area and need to implement some much better record keeping methods myself! I hope each of you find what works for you and shares it with the rest of us!