+1 on ALL the above.
The only things I would add is to be very gentle with the plug wires. If they haven't been out for awhile, the caps WILL be sticky in the valve cover. I put a little bit of dilectric grease on the plug boot edges where it meets the valve cover, makes re-installation much easier.
There have been posts where the cap was NOT fully installed onto the plug. In my experiance, that's exactly why..
If you have an air compressor (not mandatory), blow out the plug holes before you pull the plugs, (just in case any crap got in there)..
And NO lube, anti-seize, anything, on the new plugs going in, just dry and clean. It'll screw up the torque readings and the plug threads (at least NGK) have a coating on the steel threads for aluminum heads..
As for the plug threads - I personally find it near impossible to readily clean the heads spark plug threads so the plug goes in smooth like it should. Because of the abrasive nature of the combustion carbon there I place a very small drop of oil on the first couple of plug threads (against Scott's wishes! ) as I feel its better than having it gall the threads when turning the plug in.
Read above about making certain the plug wire is tight in the cap before installing the CAP. About that floating rubber seal visible on the head; make certain you HEAR the click click click of the cap engaging the plug, and bottoming. << VERY IMPORTANT!!! Now watch as you push on the plug cap again, if it tries to SPRING UPWARDS, you need to move that rubber boot up the cap a tad. You want it in contact with the valve cover, but not so much tension that it lifts the cap and comes up from vibration.