I've been reading The diary of a cavalry officer in the Peninsular War and Waterloo Campaign, 1809-1815, and it's been a fascinating look at the campaign. I only began to read in the hope of learning more about how a cavalry charge was performed, but it's entirely captured my attention now.
That said, it's only one side of the campaign, and now I'm wondering what the French experience was. Have there been any English translations of French personal accounts of the campaign?
The Leonaur Press specializes in publishing a number of memoirs from the Napoleonic era and they publish several memoirs of French cavalry officers. Of the list, the two that are more frequently quoted in the literature are Parquin and de Rocca's memoirs. Marbot's memoirs are also popular, but while most Napoleonic memoirs are embellished to a degree, Marbot tended to be more extreme in his fabrications and exaggerations. Memoirs of a Polish Lancer by Dezydery Chlapowski is a good, non-French memoir by a cavalry officer who saw service both in the Peninsula and in the 1812 campaign. Although not a cavalry officer per se, Heinrich von Brandt's In the Legions of Napoleon: The Memoirs of a Polish Officer in Spain and Russia, 1808-1813 is another good window into the Polish experience of Spain. Maurice de Tascher's Campaigning for Napoleon: The Diary of a Napoleonic Cavalry Officer (1806 -1813) has the benefit of not being a memoir, so there is less of a gloss applied to his military service than memoirs written decades after the events. Finally, for secondary sources, Robert Burnham's Charging Against Wellington: The French Cavalry in the Peninsular War, 1807–1814 covers a lot of the background of the Peninsular War's cavalry.