In a land currently being created by volcanic activity everybody becomes sort of an expert. If the earth shakes or a volcano rumbles the Website of Icelandic Meteorological Office is the go-to place for monitoring the activity.
And the office has just added a brand new Website for volcano watchers that shows a map of the Icelandic volcanoes and information about current status and historic activity.
However, I guess my go-to place for monitoring volcanic activity will continue to be the earthquake section of the IMO Website and related maps where you can basically see eruption beginning via data and maps.