Well the Sunday papers have all had a exam guide or two in them. If you missed them then ask about, you might find an aunt or uncle keeping a copy “just in case”
A few of these have been published online over the past few years, but remember before you go searching the net for them, that the computing exam changed in 2005 (other subjects may have changed as well), so be careful to get the right one. I have one or two copies in school and found this one in Dundee.