In my sfdc 1 i have added a Global Actions to and calling the Vf page. The scenario is : go to all contact tab then select a contact and on that contact select a public action button which we created an it would take the id of the current record and update on a user object. Please guide me the best way I can do this.
How to Create Object and Global Actions is well documented in numerous tutorials provided by Salesforce including the Salesforce 1 App Developer Guide and the Force.com Platform Fundamentals. Between those two documents, I'd expect you to find the guidance you seek.
If you have a more specific question, then please come back and post for help with it. As your question is currently phrased, it doesn't appear to be specific to a particular issue you're experiencing. If I've misunderstood, please edit your question for clarity and I or others will attempt to provide an answer to your detailed question.