Take a look at the load-geo-tables script in www/install. It just does a "psql -f" on the .ctl file. If you've loaded the data model from www/doc/sql before loading the geo tables, you'll have to drop the tables involved before running the script.
Actually, Postgres documentation's not bad. It's just a bit sparse and not always 100% up-to-date. You can read about the COPY command, used in the load-geo-tables script, in the Postgres user's guide.
