General Data Protection Regulation

Has anyone started to consider the implications of GDPR in relation to a church magazine. They come into effect in May this year.
we are looking at the list of names of people who subscribe to the magazine - ie our distribution list
As well as our distribution lists for our magazine subscribers, I am considering how to apply the new regulations with regard the advertisers in the magazine. I keep an Access database of their names and addresses and when they should have and actually paid etc. It also has personal contact details for some, which may well not be included in their public advert, but which helps me get payment made. Any ideas anyone?
The rules of our church magazine are, that if you submit an article for publication your name will be placed at the bottom of the article so readers know who has submitted it. Articles "about people" are followed up by email back to the sender/writer of such article asking them to confirm they have permission from the person identified to submit and publish the article. No such confirmation results in the article not being published.