Make sure you unplug the dryer before you do any testing.
To check the igniter you will need an ohm meter.
You should have a reading 50 and 500 ohms.
You can also test the valve.
On the three pin valve you should have the following readings:
Between terminals 1 to 2 should read 1365 ohms + or - 25 ohms.
Between terminals 1 to 3 should read 560 ohms + or - 25 ohms.
Between terminals 4 to 5 should be 1220 ohms + or - 50 ohms.