SCT through sky mini-dish

Hi, I'm new to the whole satellite thing so please bare with me.
I've had sky digital for a while and have recentley bought a new reciever (Technomate 5000 CI with irdeto cam) as SCT are now broadcasting on sky's frequency.
My SCT card should arrive tomorrow and as far as I know i just put that card in the irdeto cam and put it all in the cam slot.
Am I right???
The thing thats bugging me since browsing the site is all the other cards available - gold, silver etc etc.
Do I need one?
There is a lot of channels on there that are 'not running or scrambled' How do I un-scramble them??
Any help appreciated.