SriLanka.travel, an official state tourism board with information about holidays, investments, studies, meetings, tourist attractions, a calendar of events, hotels and accommodation available, and a discussion forum for questions about travelling to Sri Lanka.
World Factbook of CIA has many accurate general information about geography, people and society, government, economy, communications, transportation, military, transnational issues.
Train timetables in Sri Lanka are at railway.gov.lk. Theseat reservationin publictrainsis not easyandwe don't knowthe details, please check the official website or travelling forums. Private companies (Rajadhani and Exporail) attach private wagons to publictrains. Seats in these wagonscan be booked but at a much higher price that in the public wagons.
The network of buses is very important and covers all the island, any villages. No online timetable available. You have to go to ask to the bus station or to your guesthouse. Ticket has to be taken and paid in the bus.