In addition to several books that have been written about
(either specifically or as chapters in books which discuss
shell programming), one can find out more about
(including suggestions of a few books) from the FAQ
sed-users mailing list, available from:
Also of interest are
sed tutorials and other
sed-users mailing list itself maintained by Sven Guckes.
To subscribe, visit http://groups.yahoo.com and search
sed-users mailing list.