I went with the advise and purchased a code reader:
http://talktomycar.co.uk/Shop/Code_Readers/mj004.htm
It has identified 4 faults and the manual describes them as:
P0300 Random/multipul cylinder misfire
P0301 Cylinder 1 misfire
P0302 Cylinder 2 misfire
P0303 Cylinder 3 misfire
So its given a good direction to the problem but I don't know which cylinder's are 1,2 & 3 as I sit in the drivers seat? Also, I'm not really sure what to check other than the wires for the spark plugs? Any other ideas? Thanks.