How much should I go?
 

How much PSI should I tune my Supercharger up to? And what can I do to do it? (Im learning as I go with the whole forced induction game.)

50,000psi

seriously though it depends on what your motor can take, how much tuning youve done, what gains you want, and how much money you have.

I would tend to say don't swap a pulley to run more boost than the one it came with unless you get forged internals. A probe message board would be able to help you lots more than here...