This is one of the first books I bought on the Peninsular War, and I still think it's a great introduction to the topic. A fairly slim volume (larger format), it packs in a surprising amount of material. It covers the war basically chronologically, starting with the flight of the Portuguese royal family and ending 'in the streets of Toulouse'. Obviously every battle cannot be covered in detail. The entire period is covered as more of a continuous narrative, extensively illustrated with (black-and-white) pictures of generals, contemporary illustrations of battles, campaigns, countryside and equipment, plus diagrams of major battles. Highly readable, I'd recommend it to anyone starting out on the Peninsular war as a great overview.