If you're already got a standard Sky digibox, you can upgrade to Sky+. Here's a few things you should know:
A standard Sky box needs a single feed from the satellite dish. The Sky+ service uses two feeds. not one - this because the Sky+ service allows you to watch one channel while recording another. The Sky installer will connect an extra feed from the dish to your Sky+ set-top box. More on installation
Sky+'s functionality is free as long as you subscribe to any Sky package, otherwise you'll need to pay £10 a month to use the Sky+ box to record and pause shows and films. More
For more, or to arrange Sky to visit and upgrade you to Sky+, go to sky.com/shop/boxes/sky-plus-box.
hope this helps x