Squeaky Clutch

Ok, every time i push my clutch pedal in, there is an awful squeak coming from the underside of the car. I got under it today to try and pinpoint the problem, and tried to take the (i guess clutch fork, never messed with tranny stuff before) cover off from the driver side of the tranny, but it seemed like none of my sockets, metric or standard, were fitting the bolt. 3/8 was close, but still turning on my 12 pt sockets. Anyone know what size this bolt is? I will try 6 pt sockets tomorrow, the 12 pts were all i had at the time, maybe that will do it. Anyway, i still havent been able to troubleshoot it yet, so does anyone know what this might be? Hopefully my clutch isnt going south, just got a new one less than a year ago...

I ran a search and most of the posts said TOB, but im not sure this is the problem. They seemed to be describing a constant squeaking while the car is on, and then going away when you press the clutch in. I can have my car turned off in neutral and push the clutch in, and the squeak happens while im pushing the pedal, like an "opening a squeaky metal gate" type of sound. Is it in my cable or inside the trans?