Locating resources on Ubuntu
While you can certainly work with Odoo under the Windows environment, most of the community is in agreement that it is better to run your Odoo server under Ubuntu. Here are some resources that can help you get started with Ubuntu.
The official Ubuntu website
If you are planning on working with Odoo and Ubuntu, you will want to begin by getting familiar with the official Ubuntu website at http://www.ubuntu.com/.
Directly download Ubuntu server or desktop
Resources for downloading Ubuntu in various formats and configurations are available at http://www.ubuntu.com/download.
The official Ubuntu documentation
The official Ubuntu website has a comprehensive set of documentation that is a great reference for troubleshooting your Odoo installation, which is available at https://help.ubuntu.com/.