su - postgres
createuser testuser
createdb test --encoding='utf8'
(if you like to have utf-8 encoding) or
createdb test
psql postgres
ALTER USER testuser WITH ENCRYPTED PASSWORD 'supergeheim';
\q
echo "local cmsms cmsms md5" >>pg_hba.conf
(/etc/postgresql/8.1/main/pg_hba.conf
in debian)