My husband and brother-in-law are looking into golfing in Ireland.  I know they are interested in Ballybunnion and Old Head and a few other golf courses where it is difficult to get tee times.  They are going to try to play 2 courses.  Is it best to try to book online?  Is there a golf reservation service?  Would our hosts at some of the places we are staying, be able to help us get tee times?  We will be visiting the first week in Sept.