Gosh be careful if your doing that, the volts jumping across could kill a black dog!
You can use a multimeter to check the continuity..... not sure what setting i had it dialed on but basically if you have the MM probs touching together and then turn the MM dial until it shows a number or a 1 (meaning connected and 0 for not) and then put the probs on the coils top terminals after removing the leads you should be able to test if they have continuity.
There is a value my local mechanic mentioned they should be around, but basically i found one that didnt have any continuity, i replaced it with one that did from a spare car and hey presto.
If you dont have a multimeter... buy one they can be brought for less then $10
ANd look below at those other links .... you will probably find a better explanation there.
Much safer doing electrical stuff without having to have the motor running!
Just a reminder that testing with a multimeter will not always reveal a fault with the coil pack. I tested mine last week due to the motor missing under load and they all showed the same numbers. Dropped the car off at the mechanics today and what do you know, one of the coil packs was knackered. Just picked it up half hour ago, runs like a dream.