Install PostgreSQL 9.0 on Ubuntu 11.04

To install PostgreSQL 9.0

Add already compiled ppa key
$ sudo add-apt-repository ppa:pitti/postgresql

Update you're repo & install postgres
$ sudo apt-get update
$ sudo apt-get install postgresql

Logged as postgres user and create database , user and grant all permission to users for database.

postgres$ psql template1
postgres$ create database testdb;
postgres$ CREATE USER testuser with password 'testuser';
postgres$ GRANT ALL PRIVILEGES ON DATABASE testdb to testuser;

Hope it may help you to install and configure postgres.