Garden/Planting Advice

My wife and I want to redo our front garden this Spring and Summer. We have been in the property for a couple of years but have only just decided what we would like to do with the front of the house. We have quite a clear idea of the final picture but are not quite sure of WHAT to plant and WHEN to plant to achieve it. we need someone to help us with this - we don't require anything physical - just some consultation.