Add User with Select Priviliges only.

Hi, I am new to Postgres SQL and have a task to add a user that will have permissions only to select from the database but not make any changes etc...

I do not know how to do that, can anyone provide instructions?

I have the following databases:

Name | Owner |
------------+----------+
mpower_dev | mpower |
postgres | postgres |
template0 | postgres |
template1 | postgres

I would like to grant the select only provileges to the new user on the mpower_dev database.

Thank You