Looking down at your grip... The top is 1, rotating to the right if you're right handed...
Continental is bevel 2, Eastern is bevel 3, semi western is bevel 4, and western is bevel 5 (the bottom of the racquet)
The point of reference for your hand is the base knuckle of your index finger.
Now, Most people hit the FH with a grip between Semi western (Federer uses both eastern and semi western, Nadal uses Western) however you can hold the racquet any way you feel comfortable. Rotating your knuckle towards the bottom of the racquet allows you to generate more spin by angling the face of the racquet towards the net, and forcing you to swing in a steeper path relative to the ground. grips toward western allow you to hit a higher bouncing ball more easily, and grips toward continental allow you to handle low bouncing balls more easily.
PS85, 367g/345sw, Pacific classic@58