The first thing you might want to do is look here http://forums.utherverse...UPDATED-AND-REVISED.aspx
this if full of useful information for the brand new and the seasoned pro.

Also, you can't download the images, what you purchased was a protected url that you can use at any of the properties YOU own.

How to do it:

Go to the Purchased Props Tab


Select which prop you would like to use
Copy and past the url from this window into the prop editor


Also, if you click the installation instructions link it will pop up with this handy how to screen:


If you want to be able to use the textures to start full on decorating, you will need a photo sharing account to the website of your choice, the link that Laz provided, some time, and lots of patience )

Lastly, if you would like to purchase from the decorator directly, a lot of them will have links to their showroom on the bottom of the window when you are previewing the item. Keep in mind, any textures you purchase directly from them- the textures you purchase are for you and YOU ALONE to use, as well as to be kept in a locked/private/password protected folder on your photo sharing site.

So basically if you're just doing deco at you're own places, its a heck of a lot easier to go through Uther3D

Hope this helps