Please note that AT&T SIM card locks all of their BlackBerrys and will not unlock them. Since you have an AT&T SIM card, you are OK, but you can not put another carrier's SIM card in it.
AT&T BB data plans - located here - http://www.attwireless.com/midtolarg...obileinternet/
- start at $39.99/month
Your e-mail group at work should be able to tell you if they support MDS (Mobile Data Service) on their BES, and also if they will add your BlackBerry to their BES (some companies do not allow BlackBerrys that they don't purchase to be added to the BES).