I usually wear shorts, a t-shirt not white b/c of water rides and not black b/c of heat, and a nice pair of DC's for regular rides and a decent pair of NewBalences for the water.
As far as bringing stuff, i bring my Env2, sun screen, glasses, now that i got a Zune ill bring it lolz, a towel for when i get of congo falls, or atleast its bridge lolz, and who ever i go with brings money, lucky me