jekjones is correct - local calls are $0.35 for DVC members and $0.75 for other guests ... BUT ... not all (407) numbers are local calls (Kissimmee is a long distance call) and some other exchanges may still be local (321). Check the local exchanges listed in the front of the room phone directory to make sure the number you call has a local prefix - otherwise you'll get hit with some nasty long-distance surcharges.
And for any "internal" phone calls to Disney locations, the operator can connect you at no charge. (ie Resort to Resort, Resort to Store, Resort to guest services, resort to hair dressers/spas etc.