How to assign a user to administer one content type only? I have created a content type "TestContent". I created view using the content type. I can add content using the TestContent and I can see the content just fine in view. And I am the admin. Now, I have created a role "David" and I have created a user "xpress". I also have assigned the user to the role. 

Then in Admin > People > Permission: I have selected check box for 'David' for the below items:

David: TestContent: Create new content  
David: TestContent: Edit own content  
David: TestContent: Edit any content  
David: TestContent: Delete own content  
David: TestContent: Delete any content  


I logged out as admin and logged back in as xpress but I did not see the add content, find content for the content type that he has permission. Note that this user only have the permission to add content, edit content, update content, delete content for the content type.

Can you please help?

Thanks.
The xpress is not an admin, right? So the xpress won't be able to see the admin toolbar. Have you tried accessing the link of node/add/testcontent, node/node-id/edit? was xpress able to access it? if yes then you need to provide a link/button for the xpress to see when he/she logs in. Then I think you need to use views to show the lists of TestContent where xpress can search/filter.