This tip I guess is the most questioned thing regarding Moskenes, beside the ferry timetable.
Have a look below there is the weblink to the bus connection from A to Hamnoy via Reine and Moskenes. For other connections click the link there saying 'Rutetabeller' on the left then 'buss' at the bus symbol.
This map here shows all bus connections.
Be careful when you arrive in Moskenes, there might not be any transportation available.
Make sure you check with your hosts in Lofoten and try to arrange for a pick-up as distances are not very long. There might be a minibus there, but I remember it to be very pricy.
When I have visited Lofoten in September, everything was pretty sleepy and the supermarket from the village of Å i Lofoten was closing pretty early (4 o'clock if I remember well)
However if you are feeling for something to eat/drink later in the evening, try the supermarket in Moskenes. It was open until 10PM.
What to buy: Any item you would buy in a supermarket:) Nothing special here
What to pay: A bit more pricier, but not exagerrated.
I guess only people who are bored during the wait for the ferry will find their way up to the church above Moskenes harbour (and me not waiting for the ferry ;) ). But I was surprised to find some very old grave crosses just behind dating back to 1859.