There are two types of accommodation in and around the Corbett National Park. Private Resorts & Govt controlled Forest Rest Houses aka FRHs. Resorts can be booked directly as well as through the local tour operators. Going with the local tour operators based at Ramnagar would anyday be a much cheaper option because the resorts have a bad habit of selling a bit high to their direct clients. But booking a Forest Rest House is a tricky one. Although you can book it directly through the govt website. Very limited availability of rooms and a massive demand make it very difficult for a common man to book directly. We would highly recommend getting it done through some local & reputed tour operator such as Dhikala Tourism.