My Wedding Bible contained copious amounts of cake photos. My advice is that you first decide how much you are willing to spend on such sugary goodness. I say this because when I realised my dream cake was £1,500, I was a little heart broken.
Decide on flavour or flavours. Many brides move away from the traditional fruit cake. Mine is three tiers of fruit, chocolate and carrot cake. Traditionally the top tier is kept and eaten at the christening of the couples first child, but as mine is the most delicious layer, that wont be happening.
Shop around, go cake tasting. Cakes can be a work of art, and there is so much choice now, from small cupcakes to six tiers of heaven! The Americans definitely lead the way on extravagant cakes, I am hoping it will become the norm within the UK.