New Menu Links + Link Name Change

I am wanting to add a few extra links to the top-right menu but can't seem where to add these. This is for both when logged in and out of the HelpDesk. This will go alongside where the current links: Open New Ticket | Create Account and Sign In are.

Also is it possible to change the Sign In name to Client Login? I can't seem to find where to change that also. I have searched the lang files but I must be missing something.

Thank you for your help with this David.