I would check a few things first assuming the engine turns over and sounds like it has compression (i.e it does not sound like a washing machine when turning over):
1) Is there a spark present at the plugs? If not, is there a spark present at the King Lead? If you are local I have an ignition tester you can use without disconnecting anything

. If there is no spark present at the plugs but there is at the king lead I would check the rotor arm and distributor cap next. Failing that I would check for voltage at the coil.
2) (The most common response!). However is your DME relay? Does the car start with the wire jumper trick or a new relay?
3) Have you disconnected an injector? If so, will it then fire up? This will point to an fuel regulator fault.
4) Does your tachometer bounce with the car cranking? If so the crank sensors should be working, but it may be worth checking their resistance just to be sure

. EDIT - I shall assume that the sensors are fine for now.
5) Clean out our AFM connection. That (a poor connection) can also cause a non starter but the car will generally fire up for a few seconds in this condition.