The case is not covered in RAW. There is a feat in the Races of Stone (I don't remember what it's called) that has rules on throwing someone. Without that as a guide I would say a mix of RAW and experienced-backed house rule is the best option. Here is mine:
Make sure the PC is strong enough to pick up the creature in question. If they can't lift/press the creature they can't throw them. For the roll to see how far and if he could hit what he was aiming at I use the Throw Splash Weapon. I don't base the range and damage on falling. I base them on size category and treat all damage as non-lethal.
If the same size as PC: distance of 10' max, d2 points of non-lethal damage (d4/2).
If one size small than PC: distance of 15' max, d3 points of non-lethal damage (d6/2).
If two sizes smaller than PC: distance 20' max, d6 points of non-lethal damage.
If three sizes smaller than PC: distance 25' max, d6+1 points of non-lethal damage.
If four sizes smaller than PC: distance 30' max, d6+2 points of non-lethal damage.
Note: it is possible for a thrown creature to die from non-lethal damage. It is also possible for the thrown creature to be thrown into something that will cause lethal damage (a fire, off a cliff, into spikes, etc.) In these cases only the result of the lethal damage is applied.
If the creature is greater in size than the PC, I use the Trip rules with no damage being dealt.
This rule works in my games because it leverages the rules the players have access to (Splash Weapon and Trip) and models a real world throwing situation on a simple progression chart. When throwing anything (animate or inanimate) getting it to go in the direction you want is not that hard (hence the use of the Splash Weapon rule). It's really about can you pick it up and how far are you throwing it. A PC could come across an extra-planar creature that is size category Tiny but weighs 1,400 lbs. It may be tiny but you're not throwing it.
Even people of exceptional strength can't generally throw someone their own size more than 10'. The personal being thrown is not inanimate while being thrown. They're trying to get away and will react to break their fall. If they were inanimate, they would be like a huge sand bag. Just as difficult to throw and doesn't land in a fashion that is generally harmful to themselves. This is why all the damage is non-lethal.
The greater your size to the person being thrown the more speed and distance you can attain with a throw and slightly more damage is done on impact. The greater the size of the person you are throwing the less speed and distance and thus less damage. In general, even with exceptional strength, you aren't going to be able to throw someone of greater size farther than a couple of feet (hence using the Trip rule).
The house rule also allows for balanced application by both the DM and the players without unbalancing the game.