Your question is hard to answer because there are different ways a
Blackberry can be used. Most business users have enterprise-level
support, which means your system administrator will have to configure
it to work with your corporate e-mail system and will be responsible
for the activation. In contrast, a small biz owner or individual can
set everything up themselves through their wireless carrier.

I'd start with your systems department, as it appears as if they
didn't do things they should have done before giving it to you in the
first place.