I don't think there's a walkthrough for the valve cover gaskets, but this thread has some good tips:
http://legacygt.com/forums/showthread.php?t=179627
It's not too tough. On my OB I did the passenger side, in place, without running into any complications. On the 2.5i, both sides were leaking, and the timing belt needed done so we just pulled the engine.
Good luck.