How to create read only users in SQL Server 2012

Database Version: SQL Server 2012
Step 1.
Connect to your database server.
Expand Security > Logins > New login.

Step 2.
Put the login name and  select sql server authentication  and provide password.
On this window you may/ may not select the option enfornce password policy.

Step 3.
From User Mapping option select the database you want to give access.
Tick the boxes for role membership next to public and db_datareader.
Confirm by clicking OK.

Done. The read only user is created!