As I’m learning postgresql to develop with Heroku, here are my notes on some of the basic commands that are necessary to move around within the command-line interface.

Logging in under the postgres user (this would be like root in mysql)
psql -U postgres -h localhost

To list all databases:
\list

To connect to a database (similar to use database in mysql):
\c the_database

To list tables in that database:
\d

To list the columns in a particular table:
\d table_name

To view all rows in a given connected table (just the standard sql command):
select * from the_table

To quit out of the psql command-line utility:
\q