Make a print you like without the meter. Decide which tone you want as your reference point. Don't change anything on the meter, or timer. Try to use a mid range aperture and sensible time interval to get the desired test print.
For me it is usually the first non full white tone, ie the lightest grey. So put the meter under the enlarger (start with fresh batteries!) in the area where the desired non white tone in the print came from.
If using MG papers, you can do this in white light, and add the filter later. Then if you need a high contrast grade you can always double the exposure time for grades 3.5 and up in the Ilford system.
While metering, adjust the paper speed dial until the light just comes on, or just extinguishes.
The next neg, with the same paper, exposure time developer dilution and developer temp (mostly anyways) and development time will balance the meter (light will just go on or off) where you want a just non white tone to be made. Adjust the aperture to make the meter balance. Do not worry if you are at a 'click' or not if your enlarger lens has click stops at each full stop.
Read up on Ilford's EM-10. It is a simialr such meter, although I think it uses a silcone, not cds cell.
Be aware that cds cells can 'saturate' for a while after after being exposed to bright room light, if they are set to balance on dim enlarging light in the denser portions of the negative. Get a little dark envelope to tuck the sensor into , etc.
