Adding and editing products is easy – check out the tutorial video (login required).
Your really shouldn’t. Special characters like asterisks or exclamation points can make your product not show up in search results. Also, some people might think they look silly:
You created it, but did you publish it?
Note, a product can only be published when it:
The key is to upload a square image and put it at the top of the list of images associated with the product.
When you upload product images you see them as a list:
Preview images are created automatically using the image at the top of the list. (When you upload more than one image for a product, you can drag the images up or down to reorder them.)
Here’s a non-square source image and the preview image that’s created from it:

Here’s the same image resized as a square before being uploaded and the resulting preview image:
Remember: it’s hip to be square!
Open the product in your dashboard, click the “preview” tab – there’s information there about how to disable your product. You can re-publish a disabled product at any time (but not a deleted product).