Have you tried following the steps in the install guide (this is for Ubuntu but we have other install guides in the sidebar)? I just ran through them and they worked for me when setting up a postrgres database.
The only minor issue I had was setting:local all all peer
to:local all all md5
under the local connections section in my /etc/postgresql/9.3/main/pg_hba.conf file, since I was running the postgres box off my localhost.