Q&A

 Master

Check to be sure it wasn't oil that was spilt while adding oil to engine and ran into that hole. Next thing would probably be the tube seals in the valve cover itself. After time they become brittle and lose the seal, oil runs into the hole from the seal. You would need to replace the valve cover gasket, and tube seals. You can clean out the tube with a clean cloth, hand towels etc. After cleaning up most of the oil you can wet spary a little brake cleaner in the hole or on the towel to finish cleaning the area.
Let the brake cleaner evaporate (dry) then replace the plug wire.

 Master

great answer "torque wrench"
For repair procedures there is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online