Remember to get cash out before you go into the Pleasure Beach, every cash point inside there charges you and its hassle to go all the way out, find one and go all the way back in. Also, if you can, go to the pound shop before hand and get a raincoat (yes from the pound shop) then just throw it in the bin after - theres a stall outside Valhalla that sell them for a £1 but its just made out of cling film and doesnt cover you very well.
Theres also a dryer just from where you come out of Valhalla, its probably worth using. I managed to dry almost my whole body off when I used it with a few other people and I was soaked (even with one of the Valhalla cling film macs)
Oh and btw, the Iron Bru is terrible, I queued up for ages and two of the people I was with were too scared, but its really crap. Someone spat as we went down the drop in front and it almost hit me too.