Most of Orissa's rail network ( full-orissa-map, map-east-n- north-orissa, map-south-n-west-orissa) is part of the East Coast railway( map1, map2, time-table), and a small portion is part of the South eastern railway( map, plans) of Indian Railways. For trains across India see the Indian Railways Schedule, and for trains across Orissa see the ECOR schedule. Maps from IRFCA are here. India9.com has a list of stations and trains related to Orissa.
Current railway connectivity and Indian railway websites:
New lines, gauge conversions, doublings: [Hindu-April05]
Rail freight corridor: [TOI-Oct20-05]