Your Etsy Mini
What I do is open my Etsy in one tab and my blog in another tab. In your Etsy, go to the left hand side bar and under 'Promote' is a link for 'Etsy Mini', click on this and go to the link and make your mini based on the choices you are given (if you are creating this mini to go into your blog then you should keep in mind that usually any more than 2 columns will get run over because of the size of your side bar in the blogs). You want to copy the code for the javascript version (for use on personal websites and blogs). Copy the html code and then go back to your blog, under 'Customize' click on "Layout", then all you need to do is click on the box that says "Add a Gadget" to your side bar. Once clicked, just scroll down the listed widgets until you see the "HTML" box. Just copy and paste the Etsy mini html from your Etsy page, and click save.
Hope this helps!