Red97tj said he would do a write up but here is what I have for now.
each coil has 3 wires, 1 signal wire from the ECU, 1 12v switched, and one ground. The connector that goes to the coilpack has 5 wires, which are the 4 signal wires and the 12V that gets spit to all the coils. The ground can be put just about anywhere.
Here is a schematic of the wiring for the e36 m42
In summary, it is a very simple wiring job. You do not have to tap into the relay box or anything like that. Everything you need, save for ground, in in the connector.