PostgreSQL 9.2 Logging

I'm trying to understand how 9.2.4 logs common tasks and info in
CentOS 6.4 Linux. It appears everything is stored in
/var/lib/pgsql9/data/pg_log/postgresql-%a.log

My issue is the logging information is fairly missing / light. I only
see auth failures and nothing more. I tried to perform my 1st VACUUM
command on my database and I was hoping to see something in the logs
showing it PASSED / FAILED or even was manually initiated by a
superuser role but I see nothing...

I don't need to log every single verbose thing this database server
does but I would expect something like a VACUUM command would be
warranted to be logged, no?

#------------------------------------------------------------------------------
# ERROR REPORTING AND LOGGING
#------------------------------------------------------------------------------

# - When to Log -

^^^^

Not sure what to change here...

# - What to Log -

#debug_print_parse = off
#debug_print_rewritten = off
#debug_print_plan = off
#debug_pretty_print = on
#log_checkpoints = off
#log_connections = off
#log_disconnections = off

Do you PG veterans have any log change recommendations / changes I can
make which would help me understand what my system is doing? I don't
want to log every little thing possible and choke my disk with
informative logging but just basic 'what's going on' logs would be
awesome.

Thanks for any help!

--
Carlos Mennens