Doesn't sound like the clutch plate itself then. You'll hear the crunch as the gears engage. Its a bit like the sound you get trying to get into reverse whilst rolling forward.
Does the noise change when you depress the clutch in neutral? If so this could indicate a clutch release bearing issue.
A lot of boxes develop a whine in the lower gears, a change of gearbox oil sometimes sorts this out. Does the squeek stop after a while or does it just squeek as you move the gearstick? This could be caused by a stiff linkage, I put some grease on mine and this made the gearchange a bit smoother.