The Co-Founders, Regina Obe and Leo Hsu have written several books on these topics:
- PostGIS In Action (in 3rd edition in works)
- PostgreSQL: Up and Running (in 3rd edition)
- pgRouting: A Practical Guide (currently in 1st edition, with 2nd edition in works)
They are also maintainers of bostongis.com, postgis.us (the PostGIS and PostGIS related book sites), and PostgresOnline.com providing articles on various PostGIS/PostgreSQL related topics and presentations they’ve done in the past.
They also maintain the PostGIS Bundle for EDB Windows Stackbuilder package and provide windows builds for PostGIS, pgRouting, and other PostgreSQL extensions.