Hey you where right the first time.. the only thing is you didnt have to say " its where the valves are located" because its the only place the valves can be =)... but you say you see moisture on the valve cover? umm dunno if its usual. but my guess if it rained that day or sum maybe moisture got on it? it shouldnt be a problem unless it not water an its somthing else like a broken hose spraying fluid in the engine area.
Check for cracks in your hoses or losen caps make sure everythings tight and right.