add top "welcome" on to my site?

[Metura]

well i would like to add the
"Welcome, -username- Notifications Myprofile Settings Logout"

onto my site, how would i go about doing this without using iframe?
also how would i make it check if the user is logged in before showing that, or if not show an login/sign up button

Sorry if i am posting in the wrong section but i felt this was the appropriate section for it.

One more thing, I'm no super forum pro, so i don't know any of the variables being used and what not.