with regard to Steve in sidmouth's post about transport, if you talk nicely to the driver of the 157 (Exmouth) Stagecoach bus from the triangle, some will let you off at the campsite.
If coming in from Exeter on the 52, ask for the Ice House Lane bus stop. It is the third one after you pass Waitrose. Ice House Lane to the campsite will be on the other side of the road about 50 metres back. If you ask for core Hill you might end up being dropped off before Waitrose and have a long walk.

For anyone travelling from the southeast, it could be worth noting that Honiton is on the Waterloo-Exeter line, so you can use a Network Railcard to get a reduced fare off-peak.