Good online discount if you book direct on www.eastcoast.co.uk and get to Lincoln and back from £18.70 in total.
Or go to www.eastcoast.co.uk/special-offers/3plus/ if there's between 3 to 9 of you can get a further THIRD off the fare. (And there should be!)
Any railcards, of course, will bring the cost down further.
Best Singles*
London King's Cross 08.10 - 10.21 Lincoln - £9.35
London King's Cross 09.10 - 11.21 Lincoln - £10.00
London King's Cross 11.30 - 14.05 Lincoln - £9.35
Lincoln 17.28 - 20.10 London King's Cross - £10.00
Lincoln 18.26 - 21.16 London King's Cross - £10.00
Lincoln 19.35 - 22.47 London King's Cross - £9.35
*All of these services require a change at Newark North Gate and a walk to Newark Castle, plenty of time to get the connecting train and vice-versa, or Peterborough.
Read more here: http://en.wikipedia.org/wiki/Newark_North_Gate_railway_station
Station to Stadium
Lincoln Central train station is around a 15min walk to the ground.
Turn 'left out of the train station and walk up to the traffic lights next to St. Mary's church. Turn left at these traffic lights onto the High Street, walking over the railway level crossing.
Walk along the High Street (passing many good pubs) for approx 10 minutes before turning left into Scorer Street. Walk along Scorer Street until you come to a bridge across the Sincil Drain river.
Turn right immediately after crossing the bridge onto Sincil Bank, the ground is straight ahead.
Alternatively there is a shorter route (but you miss those fine pubs!)
Come out of the station and turn right to go down the road. About 30 yards ahead on your right you will see some steps and a bridge over the railway.
Go over the bridge and once on the other side follow the road down to the ground.
I think we're take the scenic route!
Station: top right, the blue blob; Stadium: bottom right, the clue's in the name
(Thanks to www.footballgroundguide.com for stadium directions.)