Author and pastor Tim Keller talks about writing as a pastor, recommending young pastors to give all of their time to their ministry and plan to write later. They can write short pieces now, if they feel compelled to write, but he suggests they wait for greater maturity before they tackle whole books. He also recommends reading:

That is far and away the most important discipline. You must read widely in general for years before you become capable of recognizing good writing. And then before you write a book on a subject, you should read 20 or 30 good books on the subject carefully and skim another 20 or 30. If you just read three or four (and refer to another three or four), your book will be largely a rehash and will offer few fresh insights.