The train station is right in the middle of Coventry and The Ricoh is right on the edge, it will cost about £7 each way in a taxi.
If you stop in a hotel won't you want to get rid of your luggage so you will have to come from the Hotel.
As for hotels it depends what you want, the big ones like Travel inn etc are quite a distance away, There if a formula one in the town centre (which is useful if Showmasters puts the buses on again from the station), other than that people stopped in smaller ones that were withing walking distance (about 10-15 minutes away) I don't know the costs or exact locations.
Emma