There are many ways to get started with ERPNext.
If you just want to check out the user interface and feel the application, just see the demo at:
If you like the feel and want to setup your own company, you can try a 30 day free trial (no credit card details required) at ERPNext.com
ERPNext.com is managed by the organization (Web Notes) that publishes ERPNext and you can do a trial run with your own account by signing up on the website.
You can also decide to host your application at ERPNext.com by buying the hosting plans. This way you also support the organization that has developed and keeps improving ERPNext. You also get one-to-one functional (usage) support with the hosting plans.
To avoid the trouble of installing an instance, ERPNext is available as a Virtual Image (a full loaded operating system with ERPNext installed). You can use this on any platform including Microsoft Windows.
Click here to see instructions on how to use the Virtual Image
ERPNext reasonably easy to install on a Unix like operating system and requires:
to be installed.