Short answers, pulled from the story.
Brian Sibley and Michael Bakewell shared the scriptwriting duties for the series. Sibley served as the lead writer while Bakewell joined him to help adapt the books into 26 half-hour episodes.
The serial first broadcast from the 8th of March to the 30th of August 1981 on BBC Radio 4. Episodes aired Sundays between noon and 12:30pm with repeats on Wednesdays from 10:30pm to 11:00pm.
The serial notably excludes Book 1 sequences involving Crickhollow, the Old Forest, Barrow-wights, and Tom Bombadil. Writers decided to excise one large episode rather than dramatically reduce several others.
Ian Holm portrayed Frodo Baggins while Peter Woodthorpe voiced Gollum and Sméagol. Michael Hordern played Gandalf and Bill Nighy appeared as Sam Gamgee under his credited name William Nighy.
Commissioners decided the series should consist of 26 half-hour episodes spanning six months. Editors later condensed the 26-part series into 13 hour-long episodes for a second run from July to October 1982.