Howdy John,
Ok, rough, basic guideline for this sort of thing.
1. Visual inspection - check for things that are out of the ordinary
2. Check all your fuses - in cab and engine bay, replace all that are blown, sometimes some circuits are in wierd places, like the horn fuse might also be for something critical. Also check your battery terminals and make sure your battery has enough charge
3. Check that you have the three things for an engine to run - fuel, air and spark. Check spark on all plugs since they may run individual coil packs/ignitors, just remove the plug from the head and leave it plugged in while cranking, use insulated pliers or such to hold the thread of the plug on the block or engine somewhere to earth it. Use a test light to check for injector pulse, put the light accross the two pins of the plug on the harness side, if it blinks on all plugs that's good. Check fuel is getting to the injectors(you said that it is probably ok), you should be able to smell fuel after cranking too. Make sure that your air intake is not blocked, check filter and try starting with your foot on the throttle slightly to make sure air is getting to the cylinders.
After these easy tests, you're really gonna need a workshop, get someone to have a look at it.
Let us know how this goes and what the problem was if you find out.
Slim
