Mark,
Check your power steering fluids first. To do this you need to locate the power steering fluid reservoir (assuming that your car has been fitted with P/S that is!) which is located on the left hand side of the engine between the fuel injection pump and the distributor, just next to the oil dipstick (see picture below).
The lid of the reservoir is held in place by a butterfly nut, which you can undo by hand. The reservoir should be near full with power steering fluid (clear red usually). If this is low or missing, then it would need a top up with power steering fluid. You can obtain this from any car maintenance shop (Halfords for example). I believe the total fluid capacity is 1.4L.
If the fluid is found to be low or missing, then it may be advisable to look for leaks in the power steering system. Low fluid levels or leaks in the system may give the symptoms you describe.
You can examine for leaks quite easily by using a torch and a bit of paper towel. Start by tracing the rubber hoses & metal pipes draining into and out of the reservoir to examine for any sign of leaks. Look on the garage floor as well, it may suggest an area where you may have a leak. You will have to follow their tortuous course through the P/S pump, around the oil pan & sump through to the steering box on the right hand side (I assume you have a right hand drive car?) of the engine bay (hidden under the intake manifold).
Do all your investigation with the engine turned off…
Noisy steering may indicate air in the system so once fluids have been checked and any possible leaks have been investigated then let us know as we may be able to talk you through bleeding the PS system…. Air may also be entering through a faulty steering box seal or P/S pump, but start with the simple checks first.
Let us know how you get on
Charles