What wood drill bits are the best for drilling holes in the logs for the electric wire?
Also what is the best way to put a groove in the beams for the wire for ceiling fans?
Drill bits for wiring, use a quality brand auger bit, or a self feeding bit for larger holes 2" and up. Good brands include Milwaukee, Irwin, Bocsh, and Northwest. Its also important to have a powerful right angle (or equivilant) drill.
For a groove use a router with a plunge bit, and run it along a jig for a strait edge. Or a dado blade in a saw, or run a regular blade twice on an angle to create a v groove.