I am particularly looking to hire a) a tax attorney/CPA, b) an
attorney who's specialty is international law (esp. business law
and/or immigration law), and c) someone who is extremely savvy in IT
applications on an international scale.

It is important to find people who not only know the ropes, but also
share similar values to ours.  I don't feel obliged to describe
exactly what those values are in this forum; I would just like to know
how people generally go about finding and screening possibilities.  In
other words, what lies beyond the Yellow Pages . . . . ?

I think personal contacts would be a key factor in such a matter. For
example, if you belong to organisations whose activities centre round
those same values, you could try asking other members if they know of
someone either personally or by name.