The discussion Psuedo pointed out covers most of your questions. I can say that a Wizard can only successfully teleport to places with which he is:
1) particularly familiar
2) has some sort of regent from that area (Like the bark off a certain tree.)
3) bound himself with magic to that spot (as represented by the wizard's tome IG)
Preferably he has more than one of the above for any given location. And yes, outside of the use of the IG Tome, teleportation is GM adjudicated.