Pillow, Sleeping bag/sheets, something to sleep on eg. mattress or stretcher;
Food & water/drinks, alchohol if you're drinking;
Eski;
Enough clothes, underwear, swimmers, warm clothes, shoes, socks, and spares of all of the above;
Toiletries eg. soap, toothbrush, toothpaste, towel, deodorant etc;
Something to sleep in, eg. tent;
THINGS TO DO, you never know when you will get bored, so a pack of cards or board games are a good idea since there will be no power points;
Batteries for things like a CD player or torches.
Think about you're lighting to and what you will be cooking on.
Bring a camping chair & remember your cutlery.