Hi Phil,
I take it your question is not just aimed at UK club newsletters?
I am editor of the monthly newsletter for the Australian ex-Military Vehicle Collectors Society, the club based in Sydney, NSW. Given my location, this may seem odd, but I took it on as a stop gap when the previous editor resigned and have now been doing it for over 2 years. It is on average about 18 pages, sometimes larger if a lot of coming event news is received. Mostly emailed out, but about 30% of members still request a printed copy, otherwise there would be no restraint on page numbers. This goes out monthly, except Jan and March when there are no meetings.
regards, Richard