This is our overland route from Phnom Penh to Bangkok (from last December).
It was a five-hour bus ride from the Cambodian capital to Siem Reap and Angkor; 11 surreal days later, we made the two-day journey, via Poi Pet and Trat, to the island of Ko Chang where we stayed for a week or so.
We didn’t have a guidebook in Cambodia, but found lots of up-to-date, juicy data at the Tales of Asia overland page.