dropdown choices for products

I was told pre-sales that I could use variation feature for my site. I haven't found any instructions on how to activate that feature - other than it's under development. Perhaps I overlooked it?

Here is what I am trying to do...

I would like to take this page: http://webmasterkuwait.com/primecuts/products/australian
and create the below choices per product on each page. So for example, the first item 'Long Fed Tenderloin' will be as follows:

Long Fed Tenderloin
Quantity: <dropdown choices>
Thickness: <dropdown choices>
Marinades: <dropdown choices>

Please let me know what I can do to accomplish the above.

Thanks!