The agent books rides for a jockey, selects horses and helps with promotional events. They schedule interviews and appearances, book transport and making hotel arrangements.. They also keep records of race meetings, expenses and other regulatory requirements and business affairs. The agent gets commission on each ride and of any prize money commonly around 10%. Most agents have had a career within racing as riders. Agents must obtain a licence from the British Horse Authority to function in this role and represent a jockey or jockeys.
http://animalcareers.about.com/od/Equine/a/Jockey-Agent.htm USA site with helpful information