hmm..
i would start with the simple stuff, check for signs of fluid leakage from the master cylinder (i think thats in the footwell) and the slave, near the clutch fork on the gearbox casing. also like the steveO says, check the clutch fluid levels, and colour of the fluid. if its black your seals in the master or slave cylinder are going.
If the pedal was creaking, it may be that the pedal box has sheered, it is weak by design, and when mine broke the pedal still worked, but i could not engage gears. the pedal box is what the pedal mounts on to..
Do a search for the pedal box breaking. find the post with photos and check that against yours.. you should be able to spot any broken metal and or lateral movement in the pedal box.
Then check all the hydraulics that feed the clutch.
Then start to worry about collpased thrust bearings and dead clutches.
can you select any gears, 1-5 or just not 1,3 or 2,4... ?