At Holt uncensored there is an old but definitive list of don’ts with regards to writing.
I produce the newsletter (bulletin) for my church and try at all times to maintain a high standard of English, but know that I often fail. The above list helps to identify common mistakes, although goes into little detail on specifics such as there/their etc. which it assumes writers should know.
Not all the points are relevant for church publications but they are definitely worth being aware of if you do not want to turn readers off.