SharePoint 2013 PowerShell Script to add listitem using REST

Hi ,

I want to develop a SharePoint 2013 PowerShell Script to add a list-item using REST. As of now I am trying to use the Invoke-RestMethod , but am getting lot of error (with parameters , authentication errors) . When I search online I am getting the content related to the Syntax and all but not getting any good sample to do this specific activity. I am able to find samples for creating lists , list properties , update but nothing for adding list-item in specific. 

Can someone guide me to a resource where I can find this specific code snippets or samples. 

Appreciate your help , thank you.

Regards,

Venkat

Venki