Antirrhinums (snap dragons) are good for bedding colour and don't need much looking after, just snap the spikes off when the flowers fade and they should sent up another flower spike. Petunias are good unless the summer is wet, geraniums give good show, Cosmos are taller and flower for ages if you deadhead, bedding begonias spread and give a carpet of red, pink and white. Yellow tagetes give a lovely splash of yellow which brightens up the garden and lasts well into Autumn.