The 4 basics I was taught during survival training were:
Food, Shelter, Water and Warmth.
The terrain, weather and climate will obviously determine what priority you put these in. Having recently completed a lengthy charter going to over 50 airstrips between Kalumburu and the Nullabor I know the first thing I always went for when I got out of the plane was the water. Treat it like fuel - if you can carry it, then do so as you will never have too much! As Aussiebert said, one of the best water carriers are the used softdrink plastic bottles. They're just about indestructable and chances are if they don't survive the forced landing, you won't either.
In a survival situation your passengers will turn to you to get them out. After all, you got them there in the first place.
Avoid the temptation to "Go for Help" or let any one else wander off. Bad enough for SAR agencies to have to deal with one search without compounding the issue. Unless you are positive you know where you are and know for sure other people are within a short range. Chances are, if AUSSAR know the approximate area that you have gone down, they will be calling known properties along your route.
ERSA has some basic info for survival which may be useful.
Oh yes and if you're a smoker, don't forget a couple of extra packets of Winnie Blue's
