While you can certainly work with Odoo under the Windows environment, most of the community agrees that it is better to run your Odoo server under Ubuntu. At the time of writing, the latest stable release version is Ubuntu 18.04. Here are some resources that can help you get started with Ubuntu.
Locating resources on Ubuntu
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 downloading the Ubuntu server or desktop
You'll find resources...