If your using a American cookbook the following information will be helpful, since many of the common cooking ingredients are called by different names:

British                  American

Plain flour             All-purpose flour
Strong flour           Bread flour
Single cream         Light cream
Double cream       Whipping cream
Caster sugar          Granulated Sugar (10X)
Demerara sugar    Brown Sugar
Treacle sugar         Molasses
Dark chocolate        Semi-sweet chocolate