Tent

I really would recommend getting a fairly decent tent as a few of my friends bought really cheap ones and them either blew away, ripped or leaked. One of my friends even woke up in a massive puddle! Also once you have bought the tent I would recommend trying it out in the back garden first. I arrived on site with mine and discovered that easy build meant standing in the rain attempting to read impossible instructions while trying to differentiate between poles A and b both of which were almost identical! I also found when I was choosing a tent that when they say four man tent they mean four small men with no bags, therefore I would check you are going to actually have enough room for you and your friends.
When your tent is up I would recommend keeping as much of your stuff as possible inside the tent as on the Saturday morning I found a very hung over guy who had lost his shoes trying to steal my friends! I gave him a can of tennants and sent him on his way :).