I'm getting an awful squealing noise every time I start my 1996 Lantra, which goes away a few minutes after the engine heats up. I'm told I need to tighten the belts, - I understand theres three belts, the power steering, the aircond and the alternator (main) drive belt. Can anyone guide me on how to tighten these belts, are there nuts and bolts I need to tighten etc? Any help appreciated.

I am getting the same on my 99 Lantra but only when I start using the steering. The power steering belt seems tight enough so I have concluded it must be the alternator belt which also drives the water pump pulley which in turn drives the power steering belt. To adjust the alternator belt you have to slacken the clamp nut on the front of the alternator, slacken the alternator pivot bolt at the back of the alternator and then use the adjuster to wind out the alternator a little until you get rid of the initial squeal. This belt should be pretty tight but with about 5mm deflection when pressed in the middle of a long run. Its difficult to get to the long run with the wing shield on so just try tightening it a bit and see if that improves the squeal. I hope to do mine at the weekend.
If you need to adjust the power steering belt itself, you just undo the clamp bolt and pivot bolt and use a large screwdriver in the slot to lever out the pump and tension the belt. About 5 to 10mm depression on the belt should be fine when pressed reasonably hard midway with a finger.