So i was changing out my plugs today and my last plug had a little oil on the bottom. I looked down into the hole and it was dry so it only got on the plug where it threads in?

What causes this and what do i most likely need to replace? Only thing the car has been doing is running a little rough by vibrating a lot. I haven't smelt burning oil or any black smoke out of the exhaust.

Google sez:

http://www.cargurus.com/Cars/Discussion-d322_ds487077

whens the last time you changed the oil?

5000 miles ago. Have the oil + filter on me and was about to vchange it after the spark plugs but i figured I'd wait and see what it could be.

What kind of car

You need to change the rocker cover gaskets.. they're round rubber gaskets that prevent oil from the head to go in the spark plug holes

1999 Honda Accord

I picked a valve cover gasket and spark plug seals up today and going to change them out tom or sunday.