You appear at the exact place and rotation you intended to. What direction you fall in is a completely different question.
But you normally can't teleport to the ceiling:
http://www.d20srd.org/srd/magicOverview/spellDescriptions.htm#conjuration said:A creature or object brought into being or transported to your location by a conjuration spell cannot appear inside another creature or object, nor can it appear floating in an empty space. It must arrive in an open location on a surface capable of supporting it.
Otherwise you could e.g. Divert Teleport someone to take a 100' fall if the ceiling's that high.