Eight of them cover the island. You cannot do without them. The volcano is inconveniently divided over four of the maps. Buy some touristic map or road map as well. The public transport is well organised.
Many busses frequent the roads and villages of the island.
The timetables are published in a booklet. The character of the people isn't exactly Spanish, although I can't tell what it is then. Paths Some stretches are marked. Don't trust the marking too much. The guides will give you enough clues.