Hi Maggie,
I extracted the marriages from the transcripts which Tom Corteen made from the original Maughold parish register volumes held at the church. These were personal copies which took him several years to transcribe. There are copies at the IoM FHS Library in Peel. I assume you are a member? If not, that's what I would recommend doing first, before you go there - you will find everyone very helpful and friendly.
So far as books are concerned, with your interest in Maughold/Ramsey you could have a look at Constance Radcliffe's books about both places, as well as the FHS publications: www.isleofman.com/Community/Genealogy/fhs/Publications.aspx
They should all be in the FHS library.
Sue