Changing the order of products in product listing?

I need to change the order of the products in the product listing as they are listing as I have entered them. How can I accomplish that? Now I need last products first.

Also, how can I list different types of a product on the product listing without listing all individually? In other words, I have a physical book that comes in .pdf, Kindle, Nook, etc. I made separate products for each but I want only the physical book to appear with links for other product formats. Is that possible?