I think it depends on if you are using public transport or a car.  There are a few hotels around the NEC grounds but these get booked up by traders.  If you are in a car there is a nice hotel in Sheldon, on the Coventry Road, towards Birmingham.  I have stayed there before when it was an Inkeepers.  It has a Toby Carvery which is good value for your dinner and breakfast was included in the price.  I thin it has changed hands recently and been done out so it will be nice and clean - it's now a Travelodge.  You will need to book in plenty of time though because traders stay there too.