To use Liquid Feedback you have to follow these
simple steps, which have to be done as the postgres system user (or
which ever is the database superuser):

$ createuser -d apache

$ psql 
postgres=# ALTER USER apache WITH PASSWORD 'the_new_password';

$ createdb -U apache liquid_feedback
$ psql -U apache liquid_feedback
\i /usr/share/liquid_feedback_core/core.sql
\i /usr/share/liquid_feedback_core/geoindex_install.sql
INSERT INTO system_setting (member_ttl) VALUES ('1 year');
INSERT INTO contingent (polling, time_frame, text_entry_limit, initiative_limit) VALUES (false, '1 hour', 20, 6);
INSERT INTO contingent (polling, time_frame, text_entry_limit, initiative_limit) VALUES (false, '1 day', 80, 12);
INSERT INTO contingent (polling, time_frame, text_entry_limit, initiative_limit) VALUES (true, '1 hour', 200, 60);
INSERT INTO contingent (polling, time_frame, text_entry_limit, initiative_limit) VALUES (true, '1 day', 800, 120);

and Create an invite code for an admin user:

$ psql -U liquid_feedback liquid_feedback
liquid_feedback=# INSERT INTO member (invite_code, admin) VALUES ('sesam', true);

Then you can start the periodic task of liquid_feedback_core by running
/etc/init.d/liquid_feedback_core restart

and eventually adding this to the default level

rc-update add liquid_feedback_core

For other info look at the README file