No Start Or Hard Start

Ensure battery is fully charged.
Check spark plugs.
Check fuel pump fuse(s).
Ensure ignition timing and fuel pressure are correct.
Check fuel injectors.
Check crank and cam sensors (if applicable).
Ensure timing belt/chain has not jumped.
Ensure ignition coil resistance is correct.
Ensure rotor, distributor and plug wires are okay.
Check ignition control unit.
Check coolant temperature sensor and connector.
Check throttle position sensor and connector.
Check airflow sensor.
Check anti-theft system (if applicable).
Check for contaminated fuel.
Check for vacuum leaks.
Ensure fuel pressure is correct.
Check for gasoline in oil.
Check ignition and sensor wires for proper connection.