If it's of any help Astra - the operator of the satellites that Sky comes from - has a simple guide to installing a dish and LNB -
How to receive - SES ASTRA. I'm outside the UK and found that the LNB skew (rotating the LNB in the collar) made a huge difference to the strength/quality of the signal - this is less significant for receivers in the UK but may still be worth getting optimal if you lose some channels in heavy rain etc.