My sharepoint site doesn't show the logout button. I guess i need to provide link to the signout.aspx page on the master page. If I am using v4.master, then where do i provide link to signout.aspx in the master page
In the v4.master page this is added to the master via the user control:
Which renders like:
The "Sign Out" button itself is defined in the .ascx as:
So you can add the standard Welcome control, add this link to the standard Site Actions drop down with the snippet directly above, or create a custom Welcome.ascx.
Hope this helps.