QUOTE (paws2sky @ Jul 9 2009, 09:46 PM)

To my knowledge, there is no firm guideline.
I suggest saving yourself a headache and playing it fast and loose: give them as many points as they need to do what it is they do.
-paws
PS Alternatively, play it even faster and looser: assign them dice pools for each of the actions they're likely to perform and don't sweat the minutiae.
This.
Keep in mind that, on average, 3 dice= 1 hit, the book uses 4 as cushioning. That should give you an idea of the pools required to challenge your runners.
Contacts and Adventures also has a slew of stat-blocks that provide healthy baseline.
If you have specific NPCs in mind, you could always post ideas here (along with the die pools of your runners) and let us brew up some.