I want to create an application which calls REST API of salesforce chatter. As a first Step I created an application in Manage Apps and obtained Consumer Key and Consumer secret. I gave callback url a dummy url which is not working.

I don't know what to do next. What I know is I should get access token to call APIs. Can some one help me to figure out what to do next. I'm trying all this in REST Client available for browser and I'm using Trial account.