The PostgreSQL port has a collection of "side orders":

postgresql-doc
For all of the html documentation

p5-Pg
A perl5 API for client access to PostgreSQL databases.

postgresql-tcltk
If you want tcl/tk client support.

postgresql-jdbc
For Java JDBC support.

postgresql-odbc
For client access from unix applications using ODBC as access
method. Not needed to access unix PostgreSQL servers from Win32
using ODBC. See below.

ruby-postgres, py-PyGreSQL
For client access to PostgreSQL databases using the ruby & python
languages.

p5-postgresql-plperl, postgresql-pltcl & postgresql-plruby
For using perl5, tcl & ruby as procedural languages.

postgresql-contrib
Lots of contributed utilities, postgresql functions and
datatypes. There you find autovacuum, pgcrypto and many other cool
things.

etc etc...

For procedural languages and postgresql functions, please note that
you might have to update them when updating the server. For example,
the "elog" method disappeared in postgresql-7.4, so postgresql-contrib
must be updated along with the server.

If you have many tables and many clients running, consider raising
kern.maxfiles using sysctl(8), or reconfigure your kernel
appropriately.

You should vacuum and backup your database regularly. There is a
periodic script, /usr/local/share/postgresql/502.pgsql, that you may
find useful.

To allow many simultaneous connections to your PostgreSQL server, you
should raise the SystemV shared memory limits in your kernel. Here are
example values for allowing up to 180 clients (tinkering in
postgresql.conf also needed, of course):
options SYSVSHM
options SYSVSEM
options SYSVMSG
options SHMMAXPGS=65536
options SEMMNI=40
options SEMMNS=240
options SEMUME=40
options SEMMNU=120

If you plan to access your PostgreSQL server using ODBC, please
consider running the SQL script /usr/local/share/postgresql/odbc.sql
to get the functions required for ODBC compliance.
======================================================================

To initialize the database, you should run initdb as the "pgsql" user
(if you want to use your locale for collation, edit ~pgsql/.profile
and set the locale to your preference first).

Example:

su -l pgsql -c initdb

You can then start PostgreSQL by running:

/usr/local/etc/rc.d/010.pgsql.sh start

For postmaster settings, see ~pgsql/data/postgresql.conf

NB. FreeBSD's PostgreSQL port now by default logs to syslog
See ~pgsql/data/postgresql.conf for more info

For more tips, read ~pgsql/post-install-notes
======================================================================
Specific for the 7.4.1 update:

A dump/restore is *not* required for those running 7.4.

If you want to install the fixes in the information schema you need to
reload it into the database. This is either accomplished by
initializing a new cluster by running "initdb", or by running the
following sequence of SQL commands in each database (ideally including
template1) as a superuser in psql, after installing the new release:
DROP SCHEMA information_schema CASCADE;
i /usr/local/pgsql/share/information_schema.sql

Fixes to the information schema (from HISTORY):
* Fix information schema for bit data types (Peter)
* Fix information schema view constraint_column_usage for foreign
keys (Peter)
===> Compressing manual pages for postgresql-7.4.6
===> Running ldconfig
/sbin/ldconfig -m /usr/local/lib
===> Registering installation for postgresql-7.4.6
===> SECURITY REPORT:
This port has installed the following files which may act as network
servers and may therefore pose a remote security risk to the system.
/usr/local/bin/postgres

This port has installed the following startup scripts which may cause
these network services to be started at boot time.
/usr/local/etc/rc.d/010.pgsql.sh

If there are vulnerabilities in these programs there may be a security
risk to the system. FreeBSD makes no guarantee about the security of
ports included in the Ports Collection. Please type 'make deinstall'
to deinstall the port if this is a concern.

For more information, and contact details about the security
status of this software, see the following webpage:
http://www.postgresql.org/