The thing that we always did was to serve the savory food first, then play a bit, then bring out the cakes etc- that way they can't make themselves sick by eating too many sweets!

Do fairy bread and cut it into shapes using biscuit cutters! I second anything on skewers - fruit, cheese cubes, gherkin, kebana, etc! Sausage rolls or ****tail frankfurts with sauce are always popular. Also Iced biscuits with pictures done in icing and smarties are always a huge hit with any age group! You really only need 3 - 4 savories and the same with sweets (including fruit) - any more than that they won't eat it all.
Have fun!