Tightening Rocker arms (noise in engine?)

[chinusta]

so this morning while driving to work I heard a faint ticking in the engine. I didn't stop and opened the hood to listen, but what I heard was not there before. If i gave it gas, the ticking sped up, and slowed down at idle. I have no idea what it could be, doesn't sound like my car is going to explode, in fact I think I might be the only one to notice it only because I know that it wasn't there before.... what could it be? I have never worked on an engine before. I have been around people that do though. Could it be a lifter or a rocker arm? and if i do tighten them do I have to get it on top dead center and do it one by one?? should I worry about the noise at all? I also know that adding ATF will quiet down the lifters, but I don't know if I should do that.