In order to enjoy the service, you need to do the following:
Register for the service
there is a simple form with basic information required. You will automatically be subscribed to the free service, but you can add other channels you want to include in your package. You can also select whether you want the playback service (£1 per month extra - included free with the full package).
Download the correct app for your computer / device
select from the list on the left or visit the App Store (iOS devices) or Google Play (for Android devices) and search for 'StuffedCrust'
Login to the service - your details will be remembered (so you don't have to keep loging in) but if you use the same account on multiple devices it will log you out.
The Adobe Air platform can be downloaded here (any version over 2.5 will work - select the best version for your operating system)