You'll get all sorts of different opinions....and in the end it's like anything else with guitar. Whatever feels most comfortable and works for you is the best way to do it. Just experiment and find what you get better results with. For the 45 degree thing, it's a matter of either just tilting your wrist forward more, or maybe even tilting your whole guitar UP so the neck points more towards the ceiling.

Rusty Cooley has some tips here. I recommend you watch it all, its just 5 min:
http://www.youtube.com/watch?v=eRGKTkVxcyM

Marty Friedman (my personal favorite guitarist) shreds with the weirdest most annoying hand position. It's almost like his hand is upside down and he is pointing the pick up. Watch some of his videos to see what I mean. Hard to explain.


Edit: as far as "anchoring". Just like the above, everyone has different styles. I think Michael Angelo Batio anchors with his pinkie or other fingers on the pick guard. Others just use the bridge/strings to rest the side of their hand on.