I assume if you are reading this HOWTO, you probably already meet the requirements, but here they are anyhow:
Have a working knowledge of the Pine email client (There is little to no documentation in this HOWTO on using Pine). If you need more information on using Pine, check out their main website. (see Resources)
A username/password in order to log into the Exchange Server (Exchange servers run in a Microsoft domain, so your Exchange logon will be the same as your domain logon).
Befriend the SysAdmin of your Exchange Server (You may or may not need the help of this person depending on which services are running).
The Exchange Server must be version 5.5 or greater (Exchange did not support IMAP until 5.5).
Pine started supporting IMAP with v2.0 and LDAP with v4.0. I would recommend upgrading to the newest version, at the release of this document v4.44 or at least v4.0 or greater.